Twenty-five African children from Libreville had concomitant typhoid or paratyphoid fever (Salmonella typhi, 4 children; Salmonella paratyphi A, 1; S. paratyphi B, 5; s. paratyphi C, 15) and Schistosoma intercalatum infection. In 19 children treated for both infections, no relapse occurred. In the six others, antibiotics alone were given and the Salmonella infection relapsed after 1 month. No relapse occurred after a second course of antibiotics together with treatment for the S. intercalatum infection. This observation suggests that S. intercalatum prolongs Salmonella infection, as do other species of schistosomes. The concomitant treatment of both infections is recommended.