Background Although platinum-based chemotherapy is a standard first-line treatment in advanced non-small cell lung cancer (NSCLC),further research for the safety and efficacy of combination chemotherapy in elderly patients has been required.The purpose of this study was to evaluate the efficacy and safety of gemcitabine and carboplatin as first-line treatment in elderly patients with advanced NSCLC and to evaluate the prognostic factors.Methods Eligibility included:(1) age of 70 years or more,(2) histologically confirmed NSCLC,(3) chemotherapy-na(i)ve,(4) advanced disease with stage ⅢB or Ⅳ,(5) East Cooperative Oncology Group (ECOG) performance status (PS)0-2,(6) adequate organ function.Patients received intravenous carboplatin (area under curve (AUC)=5) on day 1 and gemcitabine (1000 mg/m2) on days 1 and 8,every 3 weeks.Results The medical records of forty patients were reviewed retrospectively.Median age was 73.9 years (range,70-84.6),and there were 27 men (67.5％).Thirty-seven patients (92.5％) had ECOG PS 0-1.Adenocarcinoma was found in 57.5％.Median cycles were administrated with 4.5 per person (range:1-6).Best responses were partial response in 22 (55.0％) patients and stable disease (SD) in 13 (32.5％).The median progression free survival (PFS) and overall survival (OS) were 5.9 months (95％ CI:4.5-7.3 months) and 9.6 months (95％ CI:8.2-11.0 months),respectively.Grade 4 hematologic toxicities for neutropenia (7.5％),thrombocytopenia (7.5％) and anemia (5.0％) were observed.Histology was significant prognostic factor for PFS (P=-0.024).Conclusion Gemcitabine and carboplatin combination chemotherapy is an effective and manageable treatment option in elderly advanced NSCLC patients with good performance status.