Introduction: The seventh edition of the tumor, node, metastasis classification for lung cancer has been published in 2009. The aim of this study is to evaluate time trends of surgical outcomes and clinicopathologic factors in patients with pathological stage I nonsmall cell lung cancer according to the seventh edition of the tumor, node, metastasis classification. Methods: We retrospectively reviewed the clinicopathologic characteristics of 1249 patients with pathological stage I non-small cell lung cancer from Taipei Veterans General Hospital between January 1980 and December 2006, during the three periods of 1980-1990, 1991-2000, and 2001-2006. The overall survival, disease-specific survival, and postrecurrence survival were analyzed. Results: The 5-year overall survival rates during the three periods improved significantly: 53.7, 59.9, and 69.3%, respectively (p < 0.001). The 2-year postrecurrence survival rates during the three periods improved significantly: 10.6, 25.4, and 43.2%, respectively (p < 0.001). The percentage of female patients increased during each period: 15.4, 24.9, and 32.0%, respectively (p < 0.001). The percentage of adenocarcinoma also increased during each period: 51.2, 62.2, and 74.9%, respectively (p < 0.001). Tumor size during each period was 3.2, 3.2, and 2.8 cm, tending to be smaller when diagnosed in the last period (p < 0.001). The overall survival in patients with squamous cell carcinoma and those undergoing pneumonectomy or bilobectomy did not improve over time. Conclusions: Stage migration, improved postrecurrence survival, increased frequencies of female gender and adenocarcinoma, and decreased tumor size lead to improved overall survival over the past three decades.