The administration of external beam radiation therapy (EBRT) has been an integral part of the successful treatment of childhood sarcomas. However, EBRT has severe late morbidity in the developing child. In an attempt to deliver adequate tumoricidal radiation while preserving bone growth and organ function, 13 children with diverse sarcomas were treated with high dose rate brachytherapy (HDR). Seven patients had rhabdomyosarcoma and six patients had other soft tissue sarcoma variants. All patients were treated with disease-appropriate chemotherapy, usually according to the intergroup Rhabdomyosarcoma Study. Eleven patients received fractionated 36 Gy HDR alone at a mean of 3.5 months from diagnosis. Two patients received 10-12.5 Gy intraoperative HDR brachytherapy and additional 27 Gy EBRT. Nine of 11 patients in first remission have had no recurrences. One died of recurrent pulmonary metastases. The other patient that did recur is disease-free 21 months post-recurrence. Two additional patients were treated with HDR after tumor recurrence. One patient with recurrent Ewing's sarcoma, relapsed and died. The second is disease free 3 months after autologous bone marrow transplant. Grade 1 morbidity occurred in 46%, Grade 2 in 15%, and Grade 3 in 8% of the children, while relatively good bone and organ growth was maintained. The combination of conservative surgery, chemotherapy, and HDR offers the potential for disease control in young children while preserving bone growth and organ function.