The contribution of US, CT, and MR imaging was investigated in 25 cirrhotic patients with hepatocellular carcinoma. The following parameters were considered: lesion detection, site and size of the lesion, daughter nodules, location and/or infiltration of intrahepatic vessels, patency of portal vein and collateral vessels, signs of chronic liver disease, steatosis, ascitis, and lymphadenopathy. Our results confirm the value of US, which also allowed lesion biopsy in all cases. CT was as accurate as US in detecting the lesion and even superior in demonstrating daughter nodules. MR imaging, with conventional SE and IR sequences, was inferior since it missed 3 lesions due to motion artifacts; moreover, a smaller number of daughter nodules was seen than with CT. The authors conclude that, at present, MR imaging cannot replace US and CT; the latter, if combined with arteriography, using either hydrosoluble or liposoluble contrast agents, gives the best results in the detection of small hepatocellular carcinomas, and especially of daughter nodules which are important factors for planning appropriate therapy.