A 79-year-old man who had been diagnosed as having sarcoidosis when he was 63 year old, was admitted to our hospital because of marked thrombocytosis and leukocytosis in July 1991. The low neutrophil alkaline phosphatase (NAP) score, presence of Philadelphia (Ph1) chromosome in the bone marrow cells, and M-BCR rearrangement by Southern blot hybridization were observed. He was diagnosed as having chronic myelogenous leukemia complicated with sarcoidosis. The coexistence of sarcoidosis and leukemia has rarely been reported. It is difficult to discuss that there is not causal association between of them.