Siqueira Castro – Advogados > Brasilia, Brazil > Firm Profile

Siqueira Castro – Advogados > Firm Profile

With over 77 years of experience, SiqueiraCastro has been a key player in shaping Brazil’s legal landscape. The firm advises leading companies across key sectors—businesses that are actively driving Brazil’s development. This entrepreneurial spirit and sense of purpose fuel the firm’s commitment to delivering innovative legal solutions. More than specialists in the law, SiqueiraCastro understands the full scope of business challenges. That’s why the firm is a pioneer in delivering a full solution, end-to-end approach — combining legal expertise with strategic insight.

Areas of practice: Antitrust / Competition Law, Arbitration and Mediation, Asset Protection and Wealth Management, Compliance and Internal Investigations, Consumer Relations, Contracts, Corporate / M&A, Credit Recovery, Digital Law and Data Protection, Energy, Environmental Law, Family Law and Estate Planning, Financial and Capital Markets, Financial Operations, Government Relations, High-Volume Litigation, Intellectual Property, International Trade and Customs Law, Labor and Employment, Legal Management (Legal Controllership), Real Estate Transactions, Regulatory Law, Social Security Law, Strategic Litigation, Tax Law, White-Collar Crime.

International work: We are part of ADVOC, a worldwide network of independent law firms. Present in more than 90 countries, the entity is one of the most traditional and reputable in the legal world, with approximately 12,000 lawyers in the main cities on all continents. In Brazil, the network operates only from SiqueiraCastro.

Our firm was the founder and organizer of ADVOC in Latin America and kept working very closely with South America, Central America, the Caribbean, and Mexico members. Our global approach can be highlighted by partnerships and agreements that allow us to serve our clients on five continents, emphasizing the USA, China, Japan, Russia, India, Germany, France, Spain, and Portugal.

Awards: The impact of SiqueiraCastro in the legal and business worlds, besides being known by clients and by the market in general, is regularly recognised by specialised publications.
The following deserve special mention:

• Recognized as one of the top law firms in Brazil by Chambers Brazil (2024), with 10 partners ranked among the country’s leading lawyers in their respective practice areas.

• 2 partners ranked among the world’s top lawyers in their fields by Chambers Global (2025), in addition to 5 ranked practices.

• Ranked among Brazil’s top law firms in 14 practice areas by The Legal 500 Latin America (2025), with 29 partners recognized as leading lawyers.

• Ranked among the best firms in 24 practice areas by Leaders League (2025), with 47 partners highlighted among the country’s top legal professionals.

• Recognized in 12 practice areas by Latin Lawyer 250 (2025), with 22 partners named among Brazil’s leading lawyers.

• Named one of the most admired law firms in Brazil by the ANÁLISE ADVOCACIA Yearbook (2025), with 12 awarded practice areas and 45 partners recognized as top professionals.

• 41 female partners recognized in ANÁLISE ADVOCACIA MULHER (2025), with 10 ranked practice areas.

• Recognized among the top law firms in Brazil by ANÁLISE ADVOCACIA REGIONAL (2024).

• Ranked as one of the leading firms in Tax Law in Brazil by World Tax – International Tax Review (2025), with recognition in 4 practice areas.

• Ranked in Banking and Project & Development by IFLR1000 (2024).

• 5 partners recognized among Brazil’s top lawyers in their respective areas by Lexology Index Brazil (2025).

• 8 partners featured in 6 practice areas by LACCA Approved (2025).

• Recognized among the best law firms in Brazil for Intellectual Property and Trademarks by WTR 1000 (2025).

• Named Pro Bono Leading Light by Latin Lawyer for 15 consecutive years.

• Second place in the “Social Responsibility and Pro Bono Initiatives” category of the Lumen Awards (2022).

• Practice recognized in the DNA+FENALAW 2024 Awards in the categories of “Technology” and “Diversity and Inclusion.”

• In 2023, received the Human Rights and Diversity Seal from the São Paulo City Hall for supporting diversity and inclusion initiatives.

Social responsibility: Besides the support given to clients’ business activities, SiqueiraCastro pay special attention to initiatives that have a positive impact on society. Support social assistance actions and programs to improve the quality of life of needy and disabled people. And the firm also provides free legal services (pro bono) on a permanent basis to charitable and philanthropic institutions in various Brazilian states. SiqueiraCastro have a Pro Bono Committee, organically implemented since the 1990s to support the firm’s efforts throughout Brazil. Besides this, concentrate the social responsibility and pro bono activities through the Maria Clara Institute, which pays for all initiatives in the country with funds from SiqueiraCastro.

We also have made dozens of partnerships with entities in the non-profit sector over the last years. Currently, the firm is partnering with more than 70 institutions around Brazil. Over the previous three years, we have applied an average of 80 monthly hours to pro bono assistance, representing BRL 2 million in attorney’s fees according to our hourly rates. We want to highlight four projects to your consideration:

Case 1 – Muiraquitã: Historically, in Brazil, there is a reality of marginalization and genocide of the natives of the region. In the 1970s, there was a shared sense that the complete disappearance of indigenous ethnic groups would be inevitable.

In this context, our firm’s pro bono work is to legally protect these people, enforcing a clear objective of our Constitution, which sought to end the era of cultural and physical extermination of the indigenous population through serious and adequate state protection.

With that in mind, we start working with the Guajajara ethnic group, located in the northeast state of Maranhão, in a police investigation initiated to identify recent murders of its indigenous leaders.

The tribe has been fighting to end a history of murders for a long time, which has increased exponentially in the last 20 years, putting their people under a regime of fear and insecurity.

In 2020, the Guajajaras notified five murders in just six months, and our firm worked to ensure the police investigations ran effectively. As a result of our quick and efficient support, the investigations were completed within a few months, with the preventive detention of two suspects and a complaint filed against them. We act in the same direction, now in the Criminal Action, seeking to guarantee the maintenance of preventive prisons for the village’s safety.

The entire Pro Bono Committee supervises the work of six lawyers dedicated to this case. They are part of our São Paulo and São Luís offices and take advantage of its technological apparatus to shorten distances applying a unified strategy and approach. We also financially invest in moving people to participate in hearings when necessary.

We are in constant contact with the victims’ families to provide support and information about the procedure. Until now, we dedicated 180 hours to this case. From a broad perspective, the suspects remain in custody, which brings a feeling of protection and justice to the village. Indeed, this work will help to inhibit other criminal acts and murders.

This case leads us to sponsor the case of Juma, who is also an indigenous leader in the region of Altamira (Pará). We work on two complementary fronts: legal support in a case of domestic violence perpetrated by her ex-husband; and ii) guidance on threats and other crimes, including theft and home invasion, to which Juma has been a victim because of her political position.

We plan to keep working with indigenous tribes to assist them in their criminal demands. As a result of participating in this project, we could already carry out similar work with the Kaingang tribe, located in the country’s southern states.

Case 2 – True colors: In a country full of inequalities, pro bono legal assistance is an effective way to guarantee access to justice for those who need it most, as is the case with Miss Bruna dos Santos Guimarães.

At 29 years old, Bruna has a rare disease called Leber’s Congenital Amaurosis. It is a genetic eye disorder that primarily affects the retina. People with this condition typically have severe visual impairment until total blindness.

After years of research, an innovative treatment based on gene therapy emerges as a solution for this disease. Developed by the Spark Therapeutics laboratory in Pennsylvania (USA), the drug Luxturna® can reduce symptoms and even completely reverse the condition of blindness until then inevitable. But some issues keep Bruna away from this treatment:

1. Luxturna® was only registered by The Brazilian Health Regulatory Agency (Anvisa) in August 2020;
2. The Drug Market Regulation Chamber (CMED) stipulated the maximum price of Luxturna®, in December of the same year, at almost BRL 2 million per dose;
3. The drug is not part of the public health system (SUS) list and Bruna does not have financial conditions for its acquisition, nor to pay for the surgical procedure necessary for its application;
4. The later the drug is applied, the more cells can be compromised, affecting its effectiveness (the medical recommendation for the treatment is until the age of 30).

With the technical support of Instituto Retina Brasil and Hospital Israelita Albert Einstein, SiqueiraCastro Advogados took over Bruna’s case and pleaded in her favor against the Union. Thus, despite some similar cases being processed in court, for the first time, it was determined that the Federal Government should bear the costs of acquiring two doses of Luxturna®, which the Union fulfilled at the beginning of May.

Bruna received her treatment at the Albert Einstein hospital in São Paulo, the first product application in all Latin America.

Case 3 – Broken chains: This project aims to provide practical tools for companies to implement programs to support employees who are victims of domestic violence, demonstrating that such initiatives can generate greater engagement and good commercial results. To this end, we created free training sessions with clear guidelines to encourage companies and employees to participate, ensuring full support from our team in any event related to the topic.

The pro bono project was conceived based on dialogues about challenges faced by our clients and the growing willingness of these companies to engage in the fight against domestic violence actively. Competing firms have already replicated it under the ESG bias – which, although it may compromise the pro bono character, is very positive, as it is a topic that deserves special attention and only benefits from the diversity of agents willing to help.

Companies have already called upon us nationwide to provide specific training on the subject and design support programs for female employees who are victims of domestic violence. We keep doing it on a pro bono basis.

We also publish an article in a top-tier newspaper addressing the importance of companies keeps their eyes on the issue. In addition, we disseminated the subject internally, emphasizing our full support for women and men who might face cases of violence in their homes.

Case 4 – Pregnant behind bars: The pre-emptively arresting of Miss Jessica Monteiro in early 2018 happened six days before she gave birth. After significant repercussions in the media, she received the benefit of house arrest. However, in 2020, Jessica was sentenced to 20 months in prison and, although she is still on house arrest (for 43 months), the lower court refused to release her, determining the arrest. The situation is even more delicate considering that Jessica could appeal. Still, she didn’t because her lawyer, constituted in the records, stopped responding and defending her when she could no longer pay the fees. In addition to interrupting legal assistance, the lawyer failed to inform her of the need to seek another defender, allowing the flow of the procedural deadline. In this context, we’re sponsoring her interests, and, for now, we await the habeas corpus judgment session, in which we’ll hold an oral argument.

Clients: The firm assists more than 3,000 national and international clients that are active in different sectors, including banking, pharmaceutical, petrochemical, communication, automotive, construction, shipping, insurance, oil and gas, energy, IT, entertainment, aviation and transportation.

Lawyer Profiles

Photo	Name	Position	Profile
	Mrs Daniela Afonso	Partner	View Profile
	Mr Guilherme Reisdorfer	Partner	View Profile
	Mrs Marina de Araújo Lopes	Partner	View Profile
	Mr Francisco de Assis Brito Vaz	Partner	View Profile