From 1966 to 1983, 50 patients with extremity soft tissue sarcomas were treated with wide local excision and postoperative radiotherapy at the Mallinckrodt Institute of Radiology. The median follow-up was 70 months (range 28 to 168). Grade was the most significant factor affecting survival: all 11 patients with well differentiated tumor survived versus 6/8 patients with moderate and 17/31 patients with poorly differentiated tumors (p less than 0.01). In addition, lymph node involvement at diagnosis conferred a worse prognosis with only 2/5 patients alive after treatment (p less than 0.05). Eleven of 50 (22%) failed locally. Factors affecting local control included gross residual tumor after operation and limited treatment volume. Among the 35 patients who did not have gross residual tumor or limited treatment volume, two patients who received less than 5000 cGy failed locally versus 1/18 patients who received between 5000-6000 cGy and 2/15 patients who received more than 6000 cGy. Microscopically positive margins and a volume encompassing less than the total muscular compartment was not associated with an increase in the incidence of local failure. Eight patients developed local complication: five due to retreatment for local recurrence. Overall, 24/26 patients who are alive have had their limbs preserved with normal function.