Several studies suggest that patients with non-small cell lung carcinoma (NSCLC) of the superior sulcus fare better after radiation therapy than those patients with comparable tumors at other thoracic sites. There is limited data on stage-by-stage comparisons between patients with superior sulcus tumors (SST) and non-SST (NSST). Thirty patients had SST among 656 patients with American Joint Committee on Cancer clinically staged IIIA (n = 389) and IIB (n = 267) primary NSCLC who received definitive once-daily radiation therapy. The median patient age, sex ratio, histologic findings, grade, weight loss, and performance status were similar for SST and NSST. Minimum follow-up was 24 months, with 88% of patients followed until death. The survival of patients with SST (median, 10.3 months) was similar to that of patients with tumors at other pulmonary sites (median, 10.8 months; P = 0.39). Survival for favorable patients with performance status 0 to 1 and weight loss of 5% or less was comparable between patients with SST (median, 15.0 months) and NSST were similar for patients with SST and NSST (P = 0.48). The brain was the site of first failure in 20% of patients with SST and 10% of patients with NSCLC at other sites (P = 0.10). The lack of apparent difference in outcome of comparably staged patients with SST and NSST treated with radiation alone may have significant therapeutic implications.