Objective The standard therapy aft er failure of the initial non-fi rst line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in advanced non-small cell lung cancer (NSCLC) has not yet been established. The aim of the current study was to identify whether the 2nd TKI treatment or chemotherapy (paclitaxel-containing or non-paclitaxel regimen) is the appropriate treatment for patients with NSCLC based on the effi cacy of the initial TKIs.Methods Seventy-two advanced NSCLC patients who had accepted 2nd TKIs or chemotherapy immediately afe er failure of the initial TKIs in non-fi rst line seing from May 1, 2004 to January 31, 2010 at the Sun Yat-sen University Cancer Center were enrolled. The primary endpoint [2nd progression-free survival (PFS)] and the second endpoint [overall survival (OS)] were compared among the 2nd TKI and chemotherapy groups as well as their subgroups.Results (1) Twenty-one patients were treated with 2nd TKIs, and 51 patients were administered chemotherapy aft er failure of the initial non-fi rst line TKI treatment. There was nonsignifi cant diff erence in the responses (P=0.900) [2nd PFS (P=0.833) and OS (P=0.369)]between the 2nd TKI and chemotherapy groups. (2) In the 2nd TKI group, 9 patients exhibited PFS≥7 months. The initial TKI treatment group exhibited a longer 2nd PFS than the other 12 patients with an initial PFS<7 months (7 months vs. 2 months, P=0.019). However,these groups had nonsignifi cantly diff erent OS (P=0.369). (3) In the chemotherapy group, patients with PFS<5 months exhibited longer 2nd PFS than those with PFS ≥ 5 months in the initial TKI treatment (3 months vs. 2 months, P=0.039). (4) In the chemotherapy group,patients treated with paclitaxel-containing regimen showed longer 2nd PFS than those treated with non-paclitaxel regimen (5 months vs. 2.3 months, P=0.043).Conclusions Patients with PFS≥7 months or <5 months under the initial TKI treatment potentially benefi t from the 2nd TKI treatment or chemotherapy immediately after failure of the non-fi rst line TKIs. The paclitaxel-containing regimen may improve the 2nd PFS.However, more patient samples are urgently needed to validate these fi ndings.