BACKGROUND The aim of this retrospective study was to evaluate prognostic factors for recurrence-free survival in stage-I non-small-cell bronchogenic carcinoma. METHODS During 9 years, 338 consecutive patients were operated on for stage-I bronchogenic carcinoma. Patients with small-cell carcinoma (n = 14), prior malignancies in locations other than pulmonary (n = 41), and patients with incomplete data on prognostic factors (n = 11) were excluded. Of the remaining 272 patients 226 were men. Mean age was 63 years (40 to 81 years). The resections performed comprised 215 lobectomies and bilobectomies, 36 segmentectomies and wedge resections, and 21 pneumonectomies. According to the number of sites of dissected lymph nodes 3 subgroups were formed: group A with 0 to 4 (n = 71), B with 5 to 6 (n = 118), and C with 7 to 10 sites (n = 83). Median follow-up was 46 months. RESULTS Three patients (1.1 %) died within 30 days of operation. In 3 patients the resection was revealed to be not radical (R1). At the end of follow-up, 191 patients were alive, 174 of these without recurrence. Eighty-one patients had died, 53 associated with tumor recurrence. Four patients had died of non-pulmonary malignancies. Twenty-two patients died of causes not related to tumor disease. In 2 patients the cause of death could not be determined retrospectively. Overall 5-year survival was 65% (95% confidence interval [CI] 58-72%), recurrence-free survival 59% (CI 51-66%). Significant prognostic factors for recurrence-free survival were T stage (relative risk [RR] 1.7 for T2 vs. T1, CI 1.0-3.0), age (RR 1.9 for >70 years vs. < or =70 years, CI 1.1-3.1), adeno cell type (RR 2.3 vs. squamous cell, CI 1.4-4.0), as well as lymphangiosis carcinomatosa (RR 2.3, CI 1.2-4.4). Extent of operative resection, extent of lymphadenectomy, and sex did not influence survival. CONCLUSIONS 5-year survival of our patients was in the range reported in literature. Most patients died of distant metastases. Our retrospective study probably underestimated the occurrence of second primary cancers of the lung. Limited resection in poor-risk patients showed equivalent results to lobectomy. The extent of lymph-node resections had no influence on survival of stage-I patients, however, it must be remembered that positive results in lymph nodes shift patients to higher stages.