Ten boys with paratesticular embryonal rhabdomyosarcoma were treated in a 44-year period. Two prognostically distinct stages of the disease and appropriate treatments are described. Children with non-infiltrating tumors (stage IA) are curable (3 patients are alive and free of tumor after 8 to 44 years) and radical orchiectomy with adjunctive radiation or, preferably, chemotherapy is adequate for these patients. Conversely, in those children with infiltrative tumors retroperitoneal nodal metastases invariably develop. Early retroperitoneal lymphadenectomy with adjuvant radiation and multidrug cyclic chemotherapy is life-saving (3 are alive and free of tumor after 2 1/2 to 4 years). However, delayed recognition and treatment of retroperitoneal disease, despite agressive therapy, is frequently disappointing--2 of 4 patients died after 2 and 6 years; another, who had advanced disease, is lost to followup and also is presumed dead and 1 is alive and free of tumor after 6 1/2 years.