We review the predisposing conditions, the presenting signs and symptoms, as well as the risk factors and bacterial etiologies in children with infective endocarditis, focusing on hospital course and outcome. We conducted a retrospective analysis of 76 cases of endocarditis in 73 patients occurring at Children's Hospital of Pittsburgh from January 1958 through December 1992. The median age of the patients was 9 years (range, 1 month to 18 years). Predisposing conditions included congenital heart disease (62 patients) and rheumatic heart disease (four patients). Seventy-seven percent of the children with congenital heart disease had undergone cardiac surgery. After therapy with appropriate antibiotics was started, blood cultures for 67 patients (70 episodes of infective endocarditis) remained positive for a mean (+/-SD) of 0.7 +/- 1.41 days, and all patients who presented with fever (75 episodes in 72 patients) remained febrile for a mean (+/-SD) of 4.28 +/- 6.21 days. Secondary fever occurred in 39% of the children. Thirty (41%) of the 73 patients survived without any complications and 13 (18%) died. Fifteen children with complications required surgery. Children with endocarditis caused by Staphylococcus aureus were more likely than those with infection caused by viridans streptococci to have prolonged fever, secondary fever, and/or complications as well to require surgery.