The authors describe cases of opisthorchiasis and pseudamphistomiasis in 5 areas adjacent to the banks of the Volga, Kama, and Belaya. Metacercariae of Opisthorchis and Pseudamphistomum have been detected in the Cyprinidae. The incidence rate of Opisthorchis infection has been notified in these areas since 1957 and that of Pseudamphistomum infection has been recorded since 1989.