We reviewed the factors influencing local control of potentially curable rectal cancer in 106 patients. There was improvement in stage-adjusted local control associated with increasing use of adjuvant radiation therapy. A meta-analysis of the English-language literature through 1988 also supported the effectiveness of adjuvant radiation therapy in all but the lowest-risk patients. No effect on survival was identified in either analysis, but a reduction of up to 40% in local recurrence rates may be achieved with doses of 3000 cGy or more.