A randomized study with cisplatin (120 mg/m2) or carboplatin (325 mg/m2) plus etoposide (100 mg/m2, days 1 to 3) in 162 evaluable patients with advanced non-small cell lung cancer (NSCLC) compared response and survival after treatment. No statistically significant difference in survival rates was detected; median survival was 25 weeks for patients receiving cisplatin and 24 weeks for those receiving carboplatin. The objective response rate was 25% for cisplatin plus etoposide and 20% for carboplatin plus etoposide. Granulocytopenia, diarrhea, and nephrotoxicity were significantly more frequent with cisplatin plus etoposide than with carboplatin plus etoposide. Severe nausea and/or vomiting occurred during 59 of 77 courses (77%) with cisplatin and 48 of 75 (64%) with carboplatin (P = .13). Unlike cisplatin plus etoposide, carboplatin plus etoposide was administered on an outpatient basis. At the dose used in the present study, carboplatin plus etoposide was as effective as but less toxic than cisplatin plus etoposide for NSCLC and could be given more easily.