Radotinib is a novel and selective BCR-ABL1 tyrosine kinase inhibitor (TKI), which has shown activity and safety in the treatment of patients with chronic myeloid leukemia resistant or intolerant to imatinib. TKIs are associated with various adverse cutaneous reactions, including edema, maculopapular rash, pigmentary changes and pruritus. A 32-year-old female presented with abrupt multiple black pigment macules on the face, neck and extremities after taking radotinib for 1 year. On histopathological examination, junctional nevus with lentigenous melanocytic hyperplasia was confirmed. It is alleged that this phenomenon is due to c-KIT activation, consequently upregulating microphthalmia-associated transcription factor. Herein, we report the occurrence of lentiginosis following treatment with a novel TKI, radotinib.