BACKGROUND. A Phase III trial was conducted by the North Central Cancer Treatment Group to determine whether chemotherapy (etoposide and cisplatin) plus either twice-daily radiotherapy (BIDRT) or once-daily radiotherapy (QDRT) resulted in a better outcome for patients with limited-stage small cell lung carcinoma (LD-SCLC). No difference in survival was identified between the two arms. The current analysis examined the relation between age and outcome for patients treated during this trial. METHODS. The current study included 263 patients with LD-SCLC and an Eastern Cooperative Oncology Group performance status of ≤ 2 who were randomized to receive QDRT or split-course BIDRT. The outcomes of the 209 (79%) younger patients (age < 70 years old) were compared with the 54 (21%) elderly patients (age ≥ 70 years old). RESULTS. Elderly patients presented with significantly greater weight loss and poorer performance status. The 2-year and 5-year survival rates were 48% and 22% for younger patients compared with 33% and 17% for older patients (P = 0.14). One specific toxicity (i.e., Grade ≥ 4 pneumonitis [according to National Cancer Institute Common Toxicity Criteria]) occurred in 0% of those patients age < 70 years compared with 6% of older patients (P = 0.008). Grade 5 toxicity occurred in 1 of 209 (0.5%) patients age < 70 years compared with 3 of 54 (5.6%) older patients (P = 0.03). CONCLUSIONS. Despite having more weight loss, poorer performance status, increased pulmonary toxicity, and more deaths due to treatment, survival was not found to be significantly worse in older individuals. Fit elderly patients with LD-SCLC can receive combined-modality therapy with the expectation of relatively favorable long-term survival. Future research should focus on ways to decrease toxicity especially in the elderly. © 2005 American Cancer Society.