Background Platinum-based chemotherapy has been proved effective in patients with advanced non-small cell lung cancer (NSCLC). This study evaluated the effectiveness and safety of first-line chemotherapy with gemcitabine plus cisplatin (GEM-Cis) 3-week regimen in routine care of Chinese patients with advanced NSCLC. Methods Two hundred and twenty-one patients with NSCLC stage IIIb or IV were enrolled and 209 were eligible for effectiveness and safety analysis. The median age was 58 (range 29 to 79) years. The percents of cases in stage Ⅳ and stage Ⅲb were 52.2% and 47.8%; of Karnofsky performance score (KPS) less than 80 and 80-100 were 37.3% and 62.7% and of adeno-cancer and non-adeno-cancer were 59.8% and 40.2%. The average number of completed chemotherapy cycles was three. Measures of effectiveness included clinical benefit, significant clinical response (SCR) and adverse effects of GEM-Cis in the treatment of NSCLC at stages Ⅲb/Ⅳ.Results KPS increased from 79±9 at baseline to 86±10 after chemotherapy (P<0.01). Lung cancer symptom scale (LCSS) score of pain, dyspnea and cough increased from 77±24, 74±22 and 63±19 to 92±15, 90±14 and 86± 15, respectively (P<0.01). The clinical benefit rate was 85.2% [95% confidence interval (CI) 80.3%-90.0%]. The SCR was 89.5% (95% CI 85.3%-93.7%). Median survival time was 7.8 months (95% CI 7.1 months-9.1 months). Sixty-four patients (30.6%) experienced an adverse effect that was deemed clinically significant. Only one patient (0.5%) was hospitalized due to chemotherapy related adverse effects. Life-threatening toxicity was observed in two patients (1.0%).Conclusion First-line chemotherapy with GEM-Cis in the routine care of Chinese patients with advanced NSCLC is effective and safe. Background Platinum-based chemotherapy has been proven effective in patients with advanced non-small cell lung cancer (NSCLC). This study evaluated the effectiveness and safety of first-line chemotherapy with gemcitabine plus cisplatin (GEM-Cis) 3-week regimen in routine care of Chinese patients with advanced NSCLC. Methods Two hundred and twenty-one patients with NSCLC stage IIIb or IV were enrolled and 209 were eligible for effectiveness and safety analysis. The median age was 58 (range 29 to 79) years. The percents of cases of stage IV and stage IIIb were 52.2% and 47.8%; of Karnofsky performance score (KPS) less than 80 and 80-100 were 37.3% and 62.7% and of adeno-cancer and non-adeno- cancer were 59.8% and 40.2 The average number of completed chemotherapy cycles was three. Measures of effectiveness included clinical benefit, significant clinical response (SCR) and adverse effects of GEM-Cis in the treatment of NSCLC at stages IIIb / IV. Results KPS increased from 79 ± 9 at ba Lung cancer symptom scale (LCSS) score of pain, dyspnea and cough increased from 77 ± 24, 74 ± 22 and 63 ± 19 to 92 ± 15, 90 ± 14 and 86 (P <0.01) The clinical benefit rate was 85.2% [95% confidence interval (CI) 80.3% -90.0%]. The SCR was 89.5% (95% CI 85.3% -93.7%). Median survival Only one patient (0.5%) was hospitalized due to chemotherapy related adverse effects. Life was 7.8 (95% CI 7.1 months-9.1 months). Sixty-four patients (30.6%) experienced an adverse effect that was deemed clinically significant. -threatening toxicity was observed in two patients (1.0%). Conclusion First-line chemotherapy with GEM-Cis in the routine care of Chinese patients with advanced NSCLC is effective and safe.