Back-ground. The histologic determinants of survival after surgical resection of stage II nonsmall cell lung cancer are poorly understood. We analyzed the prognostic significance of a number of histologic features after complete resection of T1-2N1M0 nonsmall cell cancer of the lung. Methods. The case notes and histology of all patients who underwent a potentially curative surgical resection for T1-2N1M0 nonsmall cell carcinoma of the lung between 1991 and 1997 were reviewed retrospectively. The following histologic factors were recorded: histologic type of tumor; number of nodes with metastatic deposits together with their nodal station; the presence of vascular invasion, visceral pleural involvement, and cellular necrosis; and grade of tumor. The results from 98 patients were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors. Results. Univariate analysis showed that only three factors had a statistically significant correlation with a poor prognosis: vascular invasion (p = 0.002), nonsquamous histology (p = 0.005), and visceral pleural involvement (P = 0.002). Multivariate analysis revealed that all three factors were significant independent adverse prognostic indicators. Conclusions. Visceral pleural involvement, nonsquamous histology, and vascular invasion are all significant adverse prognostic factors after surgical resection of T1-2N1M0 nonsmall cell cancer of the lung. These findings conflict with previously published reports, and we advocate a prospective, large-scale study in order to clarify the prognostic significance of histologic characteristics in stage II disease.