Lung carcinoma with a basaloid pattern (BC) is classified as either a basaloid variant of squamous cell carcinoma (SCC) or as variant of large cell carcinoma (LCC) depending on the presence of a squamous component. In a previous study of 37 cases, the present authors showed that BC presented with a shorter median and overall survival. In order to confirm its clinical significance in a larger series, 90 BC, including 46 basaloid variants of LCC and 44 basaloid variants of SCC, were compared with 1,328 other nonsmall cell lung carcinoma (NSCLC) with regard to clinical features and survival. The survival of basaloid variants of LCC and SCC was comparable. Median and overall survival were significantly lower for BC than for NSCLC in stage I-II patients, with a median survival of 29 and 49 months, respectively, and 5-yr survival rates of 27 and 44% for BC and NSCLC. When disease-specific survival was considered, BC had a shorter survival than both NSCLC and SCC. Basaloid pattern confers a poor prognosis in nonsmall cell lung carcinoma, especially in stage I-II patients, suggesting that lung carcinoma with a basaloid pattern is not only a variant of squamous cell carcinoma or large cell carcinoma, but is a unique entity with a significantly poor prognosis.