Forty-six patients with pathologic clinical stage II non-small-cell lung carcinoma underwent resection with or without adjuvant radiotherapy from 1989 through 1994. These patients were analyzed to determine patterns of recurrence and survival. Surgery consisted of pneumonectomy for 11 patients, bilobectomy for two patients, lobectomy for 29 patients, and wedge or segmental resection for four patients. Adjuvant radiotherapy was delivered to 29 patients, and the median total dose was 54 Gy (range, 44-60 Gy). Median follow-up time was 23 months for all patients and 25 months for surviving patients. Twenty-six of 46 patients have had recurrence. The site of first recurrence was locoregional for 9 of 46 patients (20%) and distant for 17 of 46 patients (37%). The median time to locoregional recurrence was 18 months for patients treated with radiotherapy and 13 months for patients treated without radiotherapy. An isolated locoregional recurrence (with no simultaneous distant recurrence) was seen in 2 of 28 evaluable patients (7%) treated with radiotherapy compared with 3 of 17 patients (18%) not treated with radiotherapy. For all patients, the 3-year disease-free survival rate was 52%, and the overall survival rate was 52%. Among patients treated with radiotherapy, the 3-year disease-free survival and overall survival rates were 56% and 56%, respectively, compared with 46% and 43%, respectively, for patients who did not receive radiotherapy (p values were not significant). The locoregional recurrence rate was 33% for patients with adenocarcinoma and 15% for those with squamous cell carcinoma. The distant recurrence rates by histologic characteristic were 56% and 20%, respectively. For patients with clinical stage II non-small-cell lung cancer, postoperative radiotherapy appears to improve locoregional control. However, the preponderance of recurrences remains distant. Further study is warranted with special emphasis on control of systemic disease.