Gefitinib (Iressa^®) is an oral tyrosine kinase epidermal growth factor receptor (EGFR) inhibitor approved as the monotherapy for both local and metastatic non-small cell lung carcinoma (NSCLC). Gefitinib and other drugs that block EGFR function have been associated with cutaneous adverse effects, including follicular acneiform eruptions, xerosis, and hair texture changes. Herein, we report two cases with hair kinking after using the EGFR tyrosine kinase inhibitor, gefitinib. An 88-year-old woman suffering from metastatic NSCLC presented with lusterless and hair kinking on the whole scalp and diffuse hair loss after receiving gefitinib for 21 months. And the other patient of 64-year-old man also suffering from metastatic NSCLC presented with hair kinking after receiving gefitinib for 5 months. Furthermore, he developed several erythematous follicular papules with focal scales on the scalp. Test using a potassium hydroxide preparation produced negative results. We diagnosed these cases with EGFR inhibitor-induced hair kinking. We treated the patients with 3% topical minoxidil or oral doxycycline at a dose of 200mg/day. EGFR is present in the outer root sheath of the hair follicles and important for hair development and growth. The blockade of EGFR pathway may result in disruption of hair morphogenesis and induce hair alteration. Dermatologists should keep in mind that this adverse effect can occur in patients taking EGFR inhibitor.