We review our 10-year (June 1987-June 1997) experience in 26 children requiring early surgery due to active infective endocarditis (AIE) refractory to medical therapy. Mean age at operation was 5.0 (SD 3.5) years. Nineteen patients (73%) had predisposing factors: congenital heart disease (CHD) was the most common (10/19, 53%); endocavitary foreign materials (6/19); and previous cardiac surgery (3/19). Vegetations or valve dysfunction was detected by transthoracic echocardiography in all cases but one. Valvular location (17/26, 65%) was the most common; others locations included cardiac chambers (8/26) and intravascular thoracic aorta (1/26). Bacterial isolation was achieved in 19 patients (73%): Staphylococcus (10 patients); Streptococcus (6 patients); and Candida albicans (3 patients). The indication for surgery was progressive or persistent cardiac failure (2 patients) or infection (9 patients), or a combination of these (7 patients), despite adequate medical therapy; major embolic accident with a mobile vegetation (4 patients), recurrent pulmonary embolism with a mobile vegetation (3 patients), and mobile vegetation (> 10 mm) in left cardiac chambers (1 patient). All the patients required surgery before 6 weeks of antibiotic therapy had been completed. The hospital mortality was 19% (5/26, 70% confidential limits[CL]: 2-35%). Deaths were due to infective causes in all cases but one. No late deaths occurred in 18 patients followed up for a mean of 4.2 years (SD 2.4). Three patients needed four reoperations. We conclude that improvement in the treatment of children with AIE can be obtained with an early and accurate diagnosis, an adequate antibiotic treatment, and a more aggressive surgical approach.