Between 1970 and 1982, 102 patients received postoperative radiotherapy after attempted curative resection of bronchogenic carcinoma at The University of Texas M. D. Anderson Cancer Center. Surviving patients had a minimum follow-up of 3 years. Eight patients had pathological Stage I disease, 29 Stage II, and 65 Stage III. The 5-year actuarial survivals for patients with stages I, II, and III disease were 83%, 55%, and 38%, respectively (p = .04). Corresponding values for patients with N0, N1, and N2 disease were 74%, 56%, and 28% (p = .01). No significant differences in survival were seen based on T stage or tumor histology. Nine patients had gross residual disease following surgery, and 19 had microscopic residual disease. The 5-year actuarial survival was 78% for 12 patients without nodal disease who had known gross (4 patients) or microscopic (8 patients) residual tumor following attempted curative resection. The pathologic status of the hilar and mediastinal lymph nodes was the most significant factor affecting the frequency of metastatic relapse, with 19% of patients with N0, 33% of those with N1, and 69% of those with N2 disease developing distant disease. The low overall rate of recurrence intrathoracically (16%) confirms that postoperative radiotherapy is effective in preventing local relapse even in patients with proven nodal involvement. The impact of adjuvant radiation therapy on survival cannot be determined from these data, and further data are needed, preferably from well designed prospective studies.