Four patients with chronic granulocytic leukemia (CGL) also have Gaucher cells present in their bone marrow aspirates. In one, a child with acute lymphoblastic leukemia, the association of leukemia and Gaucher cells seems coincidental since there was a family history of Gaucher's disease. In two patients with typical CGL and one with subacute granulocytic leukemia, a biochemical abnormality is postulated. Increased granulocyte turnover in CGL appears responsible for marked overproduction of glucocerebroside which is stored in the reticuloendothelial system.