A 63-year-old male, who had undergone angiography using thorium dioxide (Thorotrast) at the age of 15 for investigation of a giant hemangioma on his left thigh, developed anemia in September 1986 (47 yrs after the angiography). A diagnosis of erythroleukemia was made from a bone marrow study which showed 56.4% megaloblastoid erythroblasts and 12.8% myeloblasts. Autopsy revealed Thorotrast deposition in the liver, spleen, bone marrow, and lymph nodes, and monotonous proliferation of myeloblasts in the bone marrow. He also had differentiated tubular adenocarcinoma of the posterior wall of the stomach.