Despite recent improvements to current therapies and the emergence of novel agents to manage advanced non-small cell lung cancer(NSCLC),the patients′overall survival remains poor.Re-challenging with first-line chemotherapy upon relapse is common in the management of small cell lung cancer but is not well reported for advanced NSCLC.NSCLC relapse has been attributed to acquired drug resistance,but the repopulation of sensitive clones may also play a role,in which case re-challenge may be appropriate.Here,we report the results of re-challenge with gemcitabine plus carboplatin in 22 patients from a single institution who had previously received gemcitabine plus platinum in the first-line setting and had either partial response or a progression-free interval of longer than 6 months.In this retrospective study,the charts of patients who underwent second-line chemotherapy for NSCLC in our cancer center between January 2005 and April 2010 were reviewed.All the patients who received a combination of gemcitabine and carboplatin for re-challenge were included in the study.These patients were offered second-line treatment on confirmation of clear radiological disease progression.The overall response rate was 15%and disease control rate was 75%.The median survival time was 10.4 months,with 46%of patients alive at 1 year.These results suggest that re-challenge chemotherapy should be considered in selected patients with radiological partial response or a progression-free survival of longer than 6 months to the initial therapy. Despite recent improvements to current therapies and the emergence of novel agents to manage advanced non-small cell lung cancer (NSCLC), the patients’overall survival remains poor. Re-challenging with first-line chemotherapy upon relapse is common in the management of small cell lung cancer but is not well reported for advanced NSCLC. NSCLC relapse has been attributed to acquired drug resistance, but the repopulation of sensitive clones may also play a role, in which case re-challenge may be appropriate. Here, we report the results of re-challenge with gemcitabine plus carboplatin in 22 patients from a single institution who had previously previously received gemcitabine plus platinum in the first-line setting and had either partial response or a progression-free interval of longer than 6 months. This retrospective study, the charts of patients who underwent second-line chemotherapy for NSCLC in our cancer center between January 2005 and April 2010 were reviewed. All the patients who received a combin ation of gemcitabine and carboplatin for re-challenge were included in the study. These patients were delivered second-line treatment on confirmation of clear radiological disease progression. The overall response rate was 15% and disease control rate was 75%. median survival time was 10.4 months, with 46% of patients alive at 1 year. The results show that re-challenge chemotherapy should be considered in selected patients with radiological partial response or a progression-free survival of longer than 6 months to the initial therapy.