A 63-year-old woman developed a pruritic exanthema on the extremities after one hour of work in her garden pond in Planegg, Southern Bavaria. As the appropriate vectors (ducks and snails) were present, we made the tentative diagnosis of cercarial dermatitis (swimmer's itch). By different serological methods (cercarial fluorescent antibody test, cercarial Hüllen reaction, circumoval precipitin test) antibodies against cercariae could be demonstrated in the serum of the patient 14 days later. Cercarial dermatitis appears worldwide, but in Central Europe the disease is often not recognized.