• All infections occurring in a busy pediatric intensive care unit (PICU) from 1982 to 1984 were characterized by site, bacteriology, acquisition status, and outcome. Standard Centers for Disease Control criteria were employed. Nine hundred sixty-five patients were admitted to the PICU. Mortality was 3.4%. Two hundred twenty-one infections occurred in 180 patients. Infection rates were 23% and 6% for total and PICU-acquired infections, respectively. Infections of the central nervous system (n=56), lower respiratory tract (n=53), and genitourinary tract (n=46) made up 70% of all infections. Haemophilus influenzae (n=39) was the most commonly isolated pathogen. Staphylococcus aureus (20%) and Klebsiella-Enterobacter-Serratia (18.3%) were most commonly noted in PICU-acquired infections. Twenty infected patients (11.1%) died in the PICU. Lower respiratory tract infections (20.5%) were associated with the highest mortality. Both PICU-acquired and community-acquired infections were associated with similar mortalities. Infected patients in a PICU have a mortality approximately 300% higher than that seen in the overall PICU population. The data presented document the importance of infection and provide information against which similar units can gauge their infection status for quality-assurance purposes.