We retrospectively evaluated the survival benefit of dispensing erlotinib after gefitinib administration in patients with nonsmall cell lung cancer. Ninety patients treated with erlotinib in our hospital were divided into two groups: G+ group patients who were treated with erlotinib with prior gefitinib administration, and G- group patients who were treated with erlotinib without prior gefitinib administration. Median survival time (MST) in all 90 patients was 275 days. MST of 22 patients in the G+ group was shorter than that of 68 patients in G- group, but this difference was not statistically significant (283 days vs 177 days, p=0. 329). MST in 19 patients of the G+group who were administered erlotinib for over 1 month was shorter than that of 49G-group patients who were administered erlotinib over 1 month. However, this difference was also not statistically significant(395 days vs 238 days, p=0. 575). Univariate analysis demonstrated that EGFR mutation unknown, time to progression (TTP) with gefitinib longer than 1 year, gefitnib administration longer than 1 year, and responder to gefitinib, suggest a better prognosis. Mutivariate analysis revealed that only TTP with gefitinib longer than 1 year was an independent prognostic factor for patients in the G+ group.