From September 1984 to July 1987, 33 children received intraoperative radiotherapy as part of a multidisciplinary tumor treatment. Their age ranged from 2 to 17 years. Tumors types: Ewing's sarcoma (n = 11), osteosarcoma (n = 8), soft tissue sarcomas (n = 5), Wilms' tumor (n = 3), neuroblastoma (n = 3), malignant pheochromocytoma (n = 1), Hodgkin's disease (n = 1), and optic nerve glioma (n = 1). In 25 patients the disease was localized while 8 had distant metastases. Intraoperative radiotherapy was used in 26 previously untreated patients as part of a radical treatment program and in 7 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. Patients with osteosarcoma and recurrent tumor in a previously irradiated area did not receive postoperative external beam radiotherapy. With a median follow-up time of 10 months (1 to 31 + months) 24 out of 33 patients are alive without local recurrence and 9 have died from tumor (5 with local disease progression). Intraoperative radiotherapy seems to be a feasible treatment which might promote local control in pediatric tumors.