BACKGROUND: Elderly patients with early-stage lung cancer are less likely to undergo tumor resection because of concerns about their ability to tolerate surgery or perceived limited life expectancy. The objective of this study was to evaluate the impact of age and competing risks on outcomes of elderly patients with stage I non-small-cell lung cancer (NSCLC). METHODS: We identified 27,859 cases of histologically confirmed, stage I NSCLC from the Surveillance, Epidemiology, and End Results registry. Patients were grouped by age (<60, 61-69, 70-79, >or=80 years) and surgical resection status. Relative survival rates were compared amongst treatment groups by age strata to determine the potential impact of surgery and the contribution of competing risks to overall mortality. RESULTS: Patients aged <60, 61-69, 70-79, and >or=80 years represented 20%, 32%, 37%, and 11% of cases. The rate of surgical resections declined from 95% of patients <60 years, to 79% of patients aged >or=80 years. While 5-year relative survival rates were somewhat lower among males >or=80 years compared with those <60 years (63.5% versus 69.2%), there were no significant differences in relative survival among resected women or unresected patients, regardless of sex. Most deaths in unresected patients were attributed to lung cancer across all age groups. CONCLUSIONS: Elderly patients who undergo resection achieve relative survival rates that are comparable to their younger counterparts. In unresected patients, lung cancer is the major source of mortality, even in the oldest age groups, suggesting that elderly patients with stage I lung cancer should receive aggressive surgical management when possible.