We reviewed the characteristics of 58 episodes of septicemia which occurred in 53 HIV infected adults over a 30-month period. This cases represented 10.1% of HIV infected hospitalized patients. At the time of septicemia, 79.3% patients were at AIDS stage; mean CD4 count was 72/mm3. Nosocomial septicemia occurred significatively more often in patients with previous AIDS defining illness and in neutropenic patients (p < or = 0.05 and p < or = 0.001 respectively). Staphylococcus coagulase negative (n = 17), Staphylococcus aureus (n = 11) and Salmonella (n = 8) were the most common organisms. The source of infection was found more frequently in nosocomial septicemia than in community-acquired septicemia (78% versus 46%; p < 0.02), mainly intravenous catheter (60%). Staphylococcus aureus, AIDS stage and nosocomial septicemia have high fatality rates. Mortality was not higher than previously reported in the general population.