A case of mixed schistosomiasis in an African female immigrant from Cameroon is reported. Schistosoma mansoni was found in a symptomatic double abscess of the lower lobe of the left lung (1981). S. haematobium was present in the stool and the rectal mucosa but the patient had no symptoms. In Africa the patient had been treated for urinary and intestinal bilharziosis with niridazole in 1979, at which time she did not present pulmonary symptoms. After her arrival to Switzerland (1980) she complained of thoracic pain and bloody purulent sputum. A solitary pulmonary infiltration in the left lower lobe and eosinophilia were noted. Tuberculosis was suspected and, despite negative bacillary findings, trial treatment with tuberculostatics was started. As a smaller infiltration appeared beside the first, left lower lobectomy was performed followed by niridazole treatment. The exceptional diagnosis of pulmonary bilharzioma should be considered in patients with a solitary pulmonary infiltration who come from an area endemic for bilharziosis or who show clinical or laboratory signs of a present or past bilharzial infection.