The objective of this phase II study was to evaluate the efficacy and toxicity of carboplatin and weekly paclitaxel combination chemotherapy in previously untreated, advanced non-small cell lung cancer (NSCLC). Patients received paclitaxel at a dose of 70 mg/m(2) on days 1, 8, 15, and carboplatin with the target dose of area under the curve (AUC) of 6 on day 1 every 28 days. Forty-six patients were enrolled. A median of four cycles (range, 1-13) were administered. Complete response was observed in one patient (2.2%) and partial response in 23 patients (50%), yielding an overall intent-to-treat response rate of 52.2% (95% confidence interval, 37.8-66.6%). The median survival time was 395 days and 1-year survival rate was 51.4%. Toxicities were mild. Twelve patients (26%) had grade 3 and three patients (7%) had grade 4 neutropenia. Grade 3 thrombocytopenia was seen in four patients (8%). Massive hematoemesis due to duodenal ulcer was observed in one patient, but no other patients experienced grade 3 or more non-hematological toxicities. There was no treatment-related death. Carboplatin and weekly paclitaxel combination chemotherapy is an efficacious and feasible regimen in patients with advanced NSCLC, and this treatment will be a reasonable alternative to the conventional triweekly regimen of paclitaxel and carboplatin.