In the era of personalized medicine, epidermal growth factor receptor (EGFR) inhibition with tyrosine kinase inhibitor (TKI) has been a mainstay of treatment for non-small cell lung cancer (NSCLC) patients with an EGFR mutation. Acquired resistance, especially substitution of methionine for threonine at position 790 (T790M), which has accounted for more than half of the cases, developed inevitably in patients who were previously treated with EGFR-TKI. At present, there is no standard treatment for patients who have developed a resistance to EGFR-TKI. Several strategies have been developed or suggested to treat such patients. This article aimsto review the EGFR-TKI re-treatment strategy and the efficacy of different generations of EGFR-TKIs in patients with acquired resistance to prior EGFR-TKI.