ABSTRACT: Specimens of the edible mollusk Concholepasconcholepas from Tocopilla, northern Chile, were found to be infected with larval forms of a fellodistomid digenean. Prevalence of infection did not significantly differ between male and female mollusks. A close relationship between first maturity and parasitic infection is suggested. Flukes invade gonadal and hepatopancreatic tissue and adversely affect structure and function of these organs. In heavy infections the penis was absent and destruction of the hepatopancreas was accompanied by disorganization of germinal tissue.