From September 1984 to March 1989, 57 children received intraoperative radiotherapy as part of a multidisciplinary tumor treatment. Their age ranged from 2 to 18 years. Tumor types: osteosarcoma, 21; Ewing's sarcoma, 19; soft tissue sarcomas, 6; neuroblastoma, 5; Wilm's tumor, 3; Hodgkin, 1; glioma, 1, and malignant pheochromocytoma, 1. In 44 patients the disease was localized while 13 had distant metastases. Intraoperative radiotherapy was used in 48 previously untreated patients as part of a radical treatment program and in 9 cases as an effort to rescue local failures (5 in previously irradiated areas). The intraoperative radiation field included the surgically exposed tumor or tumor bed, and the single doses ranged from 10 to 20 Gy, with 6-20 MeV electrons. With a median follow up time of 25 months (4 to 51 + months) 44 out of 57 patients are alive without local recurrence and 13 have died from tumor (6 with local progression). Intraoperative radiotherapy seems to be a feasible treatment which might promote local control in pediatric tumors.