Twenty-two patients with hepatocellular carcinoma and 36 without were clinically studied using angiography, computed tomography (CT), ultrasound (US) and Tc-99m phytate scintigraphy (RI). Diagnoses were confirmed by biopsy, surgery or autopsy, in all 58 patients. The judgement of multi-readers was obtained, independently. For a diagnosis of hepatocellular carcinoma, angiography was the most useful. Sensitivity, specificity and accuracy of this modality were 0.67, 0.85 and 0.78, respectively. Specificity and accuracy of US were 0.84 and 0.67, respectively, thereby US was the second best modality. CT was more useful than than RI for a diagnosis of hepatocellular carcinoma, in this series. Diagnostic accuracy of the 4 modalities in the diagnosis of liver mass were also discussed. To integrate these 4 images for a diagnosis of hepatocellular carcinoma, a multivariate analysis was made. The diagnostic accuracy of the system was considerably higher than that of any single modality.