Prouterina wescotti gen. n. and sp. n. (Trematoda: Prouterinidae N. Fam.) is described from a free-ranging black bear (Ursus americanus) which died in May 1995 in northern Idaho (USA). Adult digenetic trematodes were detected in brain, lungs, and nasal sinuses, and were likely responsible for the emaciated condition, copious nasal discharge, neurological signs, and death of the bear. Mature trematodes recovered from the bear were conical with small spines on the tegument. The anterior end was broad and tapered gradually toward the posterior. Mean (±SE) size of the mature trematodes was 3.67 (±0.08) by 2.14 (±0.04) mm (n = 80). Eggs are operculated, gold, and 68.2 (±0.42) by 41.4 (±0.41) μm (n = 75). Suckers are well developed and located in the anterior half of the body, with the genital pore just posterior to the ventral sucker. Testes are tandem and the ovary is lateral and slightly anterior to the anterior testes just posterior to the ventral sucker. The uterus is predominantly anterior to the ventral sucker and is the most distinctive feature of the trematode.