Of 2434 individuals who received Thorotrast in Portugal, mostly from 1930 to 1950, 1237 (or 51%) have been traced and followed up. As of 31 March 1974,931 of these had died: 16 from local Thorotrast granulomas, 25 from liver cirrhosis or fibrosis. 121 from malignant solid tumors (including 6 on the edge of large Thorotrast deposits, 75 tumours of the liver and other reticuloendothelial tissues, 5 bronchial carcinomas, 4 bone turnours, and 31 other solid tumours), 23 from fatal blood dyscrasias (including 12 leukemias, 8 aplastic anemias, and 3 other fatal blood diseases). These causes of death are significantly above the corresponding expected number in the general Portuguese population, and in a control group of 829 traced individuals injected with a non-radioactive contrast drug and followed up concomitantly.