At the clinic of pediatric surgery of the Sverdlovsk Medical Institute 30 children aged from 3 to 14 years were treated for subdiaphragmatic abscesses in 1979-1989. In 27 of them the abscesses occurred in 6 days to 6 months after an emergency operation. The largest group (19 children) was formed of patients who underwent operation for destructive appendicitis and peritonitis. The subdiaphragmatic abscess was found on the left side in 16 (53.3%) and on the right side in 14 (46.6%) cases. In 11 (36.6%) patients in was combined with abscesses of other localization. X-ray and ultrasonic studies and, occasionally, computed tomography were used along with clinico-laboratory methods in establishing the diagnosis of subdiaphragmatic abscesses. Operations were performed on 29 patients. One patient was treated by puncture followed by drainage of the abscess after Seldinger. The choice of the approach was determined by the localization of the abscess. The intraperitoneal approach was used in 11 cases (36.6%), Klermon's extraperitoneal approach in 16 (53.3%), Melnikov's extrapleural approach in 2, and the posterior retropleural approach in one case. Complex intensive therapy was applied in the postoperative period. Among the 30 patients one died from sepsis and developed polyorganic insufficiency.