Eleven cases of prolonged Salmonella bacteremia (2 to 12 months) occurred in patients with Manson's schistosomiasis. Blood cultures were found to be a very reliable diagnostic method if at least three blood samples from each patient were inoculated into both bile broth and trypticase soy broth and observed for 15 days. Bile broth was found superior to trypticase soy broth in isolating Salmonella organisms from the blood. Stool, urine, and bile cultures, and Widal agglutination tests were poor indicators. Patients responded equally well to parenterally administered ampicillin sodium and orally administered chloramphenicol. No relapses were noted. The pathogenesis of prolonged Salmonella bacteremia is discussed, especially in regard to the controversial role played by the underlying Schistosoma mansoni infection in producing an altered state of human resistance.