Abstract: OBJECTIVE To report an actual case and review about the interaction of warfarin and gefitinib to provide a regimen about the combination of the two drugs. METHODS Discribed a case and analyzed it,while access to relevant literature review. RESULTS With concomitant administration of gefitinib and warfarin, 26 d later the patient's INR values increased to 5.23, then discontinue the two drugs, the patient's warfarin dosage was adjusted to reach the target INR values when reused the two drugs. According to the literature analysis, when combination between gefitinib or epidermal growth factor receptor-tyrosine kinase inhibitor(EGFR-TKI) with warfarin, some patients' INR values increased, and also the risks of bleeding. CONCLUSION Concomitant administration of EGFR-TKI and warfarin, closer INR monitoring ang dose adjustments of warfarin may be necessary when EGFR-TKI initiated and discontinued.