Segmental resection was performed on 168 patients with peripheral, Stage I bronchogenic carcinoma from 1957 to July 1, 1978. Seventy-four patients (44%) had adenocarcinoma, 58 (34%) had an epidermoid type, 28 (17%) had an unadifferentiated tumor, and 8 (5%) had a bronchoalveolar variety. Ninety-five resections were done on the left lung, the most frequent procedure being removal of the superior division of the left upper lobe (38 patients). On the right side, 73 resections were done. The anterior segment was removed most frequently (19 patients). There were 3 surgical deaths, for a mortality of less than 2%. Complications requiring prolonged hospitalization were associated with air leak in 10 (6%) of the 168 patients. Survival by actuarial curve is 53% at 5 years, 33% at 10 years, and 25% at 15 years. Forty-five patients (27%) died of metastatic carcinoma. Patients with epidermoid lesions have the most favorable prognosis.