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ARTICLE · 16 JUNE 2025

The Ultimate Issue Rule: Reports Of Its "Death" Have Been Exaggerated

Singleton Urquhart Reynolds Vogel LLP
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The Ultimate Issue Rule, the common law principle which prohibited litigants from leading opinion evidence on the ultimate issue before the court, has long since been relaxed.

CanadaLitigation, Mediation & Arbitration
Evan Rankin
Evan Rankin
Jonathon Obara
Jonathon Obara

The Ultimate Issue Rule, the common law principle which prohibited litigants from leading opinion evidence on the ultimate issue before the court, has long since been relaxed. Nevertheless, recent case law suggests that the rule may be regaining some of its former potency.

In R. v. Prasad, 2024 ONCA 601, the Court of Appeal for Ontario described "the trial process, with its allocation of responsibilities" as "primordial", and stated unequivocally, that the role of the trier of fact "must never be usurped by another".1 Similarly, in Hosseini v College of Dental Surgeons of Saskatchewan, 2022 SKQB 13, a professional negligence case, the Court of Queen's Bench for Saskatchewan made clear that the "contention that the ultimate issue rule is 'dead' overstates the change that has occurred".2

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