An investigation of "swimmers' itch" at Clear Lake, Manitoba, revealed the presence of two schistosome cercariae, Cercaria elvae Miller, 1923 in Lymnaea stagnalis jugularis Say, and Cercaria sp. in Stagnicola emarginata canadensis (Sowerby); both species are known causes of the dermatitis. Five species of strigeid cercariae were found, none of which indicated any power of penetration into human skin. Copper sulphate, appropriately applied, and hand collection of adult snail hosts, are suggested for controlling schistosome dermatitis in Clear Lake.