This study was designed to evaluate the efficacy and safety of irinotecan in combination with carboplatin in previously untreated, extensive-disease small-cell lung cancer (ED-SCLC). Patients with histologically or cytologically confirmed ED-SCLC received irinotecan (60 mg/m(2) on days 1, 8, and 15) plus carboplatin (AUC 5 on day 1) every 4 weeks. Treatment was repeated until disease progression, unacceptable toxicity, or up to 6 cycles. Forty-four patients were enrolled. In an intent-to-treat analysis, the overall response rate (RR) was 75% (8 complete responses and 25 partial responses). The median progression-free (PFS) and overall survival (OS) were 5.6 and 8.7 months, respectively. The principle toxicities were neutropenia and diarrhea. Grade 3-4 neutropenia occurred in 30% of the patients and 7% of patients presented with febrile neutropenia. Grade 3-4 diarrhea occurred in 21% of the patients. A subgroup consisting of patients ≥ 65 years of age had outcomes similar to the younger group <65 years of age. The objective RR was 72% in the patients <65 years of age and 77% in the patients ≥ 65 years of age (P = .738). The median PFS and OS (<65 years vs. ≥ 65 years) were 5.3 vs. 5.6 months (P = .835) and 9.0 vs. 8.7 months (P = .648), respectively. The combination of irinotecan and carboplatin is active and tolerable in patients with ED-SCLC. This regimen could be considered as a treatment option for patients of advanced age.