Three cases of hepatocellular carcinoma are reported in young men who had been taking androgenic-anabolic steroids. The tumours were histologically similar to those described in previous reports. The tumour progressed slowly in two patients during four and seven years of observation, but in the latter bony metastases occurred. In two patients the tumours regressed after administration of the drug was discontinued. These cases strengthen the evidence that exogenous androgenic-anabolic steroids may produce liver tumours. The use of these drugs should be confined to serious conditions in which they are known to be effective. Biochemical tests of liver function and serum alphs-fetoprotein estimation are not useful as screening-tests for hepatoma in patients taking androgens, and regular isotopic liver-scanning is recommended.