The pattern and sites of recurrence were studied in 270 patients with resected Stage I (NO) or Stage II (Nl) non-small cell lung cancer (NSCLC). Survival, incidence, and type of intrathoracic locoregional recurrence versus distant extra-thoracic recurrence after surgical excision were analyzed. Prognostic parameters, such as postsurgical stage, histologic type, degree of cellular differentiation, and surgical approach, were examined to discern their influence on tumor recurrence. The total incidence of recurrence in patients with stage I and II tumors was high, with a radical surgical approach often resulting ineffective, because of incomplete locoregional neoplastic extirpation due to micrometastases. Lymph node metastases worsened prognosis, with Nl tumors demonstrating a significantly higher recurrence rate at 5 years (63%) than NO neoplasms (48%) (p < 0.01). Stage I tumors showed an elevated incidence of local recurrence (45%), with tumor T-factor making a significant contribution in such cases. N1-factor combined with an elevated T-factor (Stage II Subclass pT2Nl neoplasms) promoted a higher incidence of distant rather than local recurrence. A shorter disease-free interval was observed in patients with N tumors as opposed to NO neoplasms. Histologic type did not play a statistically significant role (p = ns) in the total incidence of recurrence. A similar total incidence of recurrence was observed in Stage I and II tumors treated by lobectomy (51%) or pneumonectomy (56%), with locoregional recurrence appearing more frequently after lobectomy.