During a six year period frorn 1963-1969, the authors studied five cases of salmonellosis associated with the hepatosplenic form of Schistosoma mansoni infection in the Trovical Medicine Clinic, School of Medicine of the Universiíy of Rio de Janeiro. The patients where aged 6 to 26 years and showed a prolonged septicaemic picture for three to eight months. Three patients were treated with chloramphenicol in daily doses of 50 vig/kg per os for 48 hours after the drop in temperature and then in daily doses of 25 mg/kg for 10 days. TIDO of these patients were treated for Schistosomiasis. The other two patients were treated with niridazole in daily doses of 25 mg/kg for 7 days. The first one was cured of prolonged septicaemia but the rectal biopsy carried out two months after the end of treatment showed viable eggs. The second one developed central nervous systeni side effects and the drug was interrupted on the fourth day. Afterwards the patient was treated according to the above scheme of chloramphenicol. All the patients were cured of prolonged septicaemia. The authors em phasize the diagnosis problems and call attention to immunological factors of the condition.