Two thousand eight hundred ninety-eight children younger than 5 years old were investigated during a 2-year period in a rural area of The Gambia for possible pneumonia, meningitis or septicemia. After clinical examination and appropriate investigations, 1014 children were diagnosed as having pneumonia, 31 as having meningitis and 100 as having septicemia. Nine hundred seven children had a final diagnosis of malaria including 702 who satisfied the World Health Organization criteria for a diagnosis of pneumonia. A bacterial etiology was established in 115 (11%) patients with a final diagnosis of pneumonia, in 25 (81%) with meningitis and in 29 (29%) with suspected septicemia. Overall the