Twenty-seven patients with biopsy proven Ewing's sarcoma were randomised to receive one of two adjuvant chemotherapy regimens for two years. Group A were given monthly courses of vincristine, adriamycin and dimethyl triazeno imidazole carboxamide (DIC); Group B received monthly courses of VM-26, adriamycin and DIC. Chemotherapy was commenced after biopsy confirmation of disease. The primary tumour was treated with irradiation to 3,000-5,000 rad and by resection in three patients. With a median follow-up of 26 months, 52% of patients are disease free. Ten patients died, seven from recurrent disease and three from complications of treatment. There was a significant difference in disease free survival rate of patients with long bone lesions (11/12) compared with patients with flat bone lesions (6/15). The disease free survival rate of Groups A and B was similar. Our results suggest that in combination chemotherapy for Ewing's sarcoma, vincristine and VM-26 have similar anti-tumour activity.