Abstract： Secondary malignant neoplasms are important late complications after chemotherapy and/or radiotherapy in cancer patients.Therapy-related malignancies include acute leukemia,myelodysplastic syndrome (MDS),lymphoma,and solid tumors.However,secondary acute lymphoid leukemia or chronic myeloid leukemia (CML) is rarely reported.[1] Here,we present a patient with P190BCR-ABL-positive CML following S-1 plus oxaliplatin therapy for gastric adenocarcinoma.The patient has given written informed consent for the use of his medical data.