OBJECTIVE To evaluate the efficacy and safety of gemcitabine in combination with carboplatin at standard rate or fixed dose rate infusion in patients with advanced non-small-cell lung cancer (NSCLC). METHODS In this prospective study, patients with chemonaive advanced NSCLC were randomized to receive gemcitabine at a standard rate (gemcitabine 1,200 mg/m2 over 30 min, the standard arm) or a fixed dose rate (gemcitabine 1,200 mg/m2 over 120 min, the FDR arm) on days 1 and 8 every 3 week cycle. In both treatment arms, carboplatin at AUC of 5 was administered over 4 h following gemcitabine on day 1 of each cycle. RESULTS From November 2003 to June 2005, a total of 42 patients, in which 7 (17%) patients had stage III(B) disease and 35 (83%) had stage IV disease, were enrolled into this study. All patients were included in efficacy and toxicity assessment. No patient had a complete response. Seven (33%) patients in the standard arm and 10 (48%) in the FDR arm had a partial response. The median time to progression and median overall survival time in the standard arm was 5.4 months (95% CI, 3.8-7 months) and 11.5 months (95% CI, 8.2-14.8 months), respectively, while in the FDR arm was 6.5 (95% CI, 4.4-8.6 months) months, 12.0 months (95% CI, 11.3-12.7 months), respectively. The most frequently reported grade 3 or 4 hematological toxicities were thrombocytopenia (38% patients in the standard arm and 43% in the FDR arm) and neutropenia (24% in the standard arm and 33% in the FDR arm). Although hematological toxicity occurred in a little higher percent of patients in the FDR arm than in the standard arm, there were no discernible differences by statistical analysis in both treatment arms (P > 0.05). And significant nonhematologic toxicities were infrequent and tolerable in both arms. No significant difference existed also (P > 0.05). CONCLUSIONS In this phase II study, gemcitabine in combination with carboplatin either at standard rate or fixed dose rate infusion was clinically effective and well tolerated in patients with advanced NSCLC.