Thirty-five children and adolescents with rhabdomyosarcoma of the genitourinary tract were treated at Memorial Hospital from August 1970 to September 1976. There were 24 boys and 11 girls, and ages ranged from 4 months to 17 years. The largest number (14) arose in the paratesticular structures, and eight others arose in non-specific pelvic sites. There were six bladder/prostate lesions, all involving both structures. Five originated in the female genital tract, two uterine body, two cervix and one vagina. Two cases had primary tumor in the soft tissue of the perineum. There were ten patients stage IA (completely resected), three stage IB (microscopic residual), six stage II (invading adjacent structures), thirteen stage III (nodal metastases) and three stage IV (distant metastases). Until 1975 all the patients were treated by one protocol (T2). This consisted of surgical removal of the tumor followed by radiation therapy (RT) (6000–7000 rads) in patients with gross or microscopic residual disease. All patients received chemotherapy (CT) consisting of sequential administration of dactinomycin, adriamycin, vincristine and cyclophosphamide for two years. In order to improve survival in stage II–IV disease and decrease delayed side effects of treatment, a new protocol (T6) was designed in 1975. This consisted of surgical removal of the primary tumor followed by RT and CT. In selected cases a cycle of RT and CT was given to reduce tumor size and enable less radical surgery to be performed. A cycle begins with RT and dactinomycin, cyclophosphamide, bleomycin, and vincristine followed by planned two weeks of rest. RT is then given with cyclophosphamide, adriamycin, methotrexate and vincristine. Following two weeks of rest, cyclophosphamide and BCNU are given and RT course is completed. Twenty-seven patients were treated by T2 protocol and nineteen (70%) are alive free of disease from two to seven years. Of the eight deaths, six were stage III or IV and died of tumor. One stage I patient died of pseudomonas pneumonia with no evidence of tumor and one stage II patient died of uncontrolled tumor. Thirty-five children and adolescents with rhabdomyosarcoma of the genitourinary tract were treated at Memorial Hospital from August 1970 to September 1976. There were 24 boys and 11 girls, and ages ranged from 4 months to 17 years. The largest number (14) arose in the paratesticular structures, and eight others arose in non-specific pelvic sites. There were six bladder/prostate lesions, all involving both structures. Five originated in the female genital tract, two uterine body, two cervix and one vagina. Two cases had primary tumor in the soft tissue of the perineum. There were ten patients stage IA (completely resected), three stage IB (microscopic residual), six stage II (invading adjacent structures), thirteen stage III (nodal metastases) and three stage IV (distant metastases). Until 1975 all the patients were treated by one protocol (T2). This consisted of surgical removal of the tumor followed by radiation therapy (RT) (6000–7000 rads) in patients with gross or microscopic residual disease. All patients received chemotherapy (CT) consisting of sequential administration of dactinomycin, adriamycin, vincristine and cyclophosphamide for two years. In order to improve survival in stage II–IV disease and decrease delayed side effects of treatment, a new protocol (T6) was designed in 1975. This consisted of surgical removal of the primary tumor followed by RT and CT. In selected cases a cycle of RT and CT was given to reduce tumor size and enable less radical surgery to be performed. A cycle begins with RT and dactinomycin, cyclophosphamide, bleomycin, and vincristine followed by planned two weeks of rest. RT is then given with cyclophosphamide, adriamycin, methotrexate and vincristine. Following two weeks of rest, cyclophosphamide and BCNU are given and RT course is completed. Twenty-seven patients were treated by T2 protocol and nineteen (70%) are alive free of disease from two to seven years. Of the eight deaths, six were stage III or IV and died of tumor. One stage I patient died of pseudomonas pneumonia with no evidence of tumor and one stage II patient died of uncontrolled tumor.