Both primary hepatoma and amebic liver abscess are probably the most common space-occupying disease of the liver in Korea, and the importance of their accurate distinction can not be overemphasized. Radiogold hepatoscanning has been widely used at St. Mary's Hospital, and recently blood disappearance rate of colloidal 198Au has been introduced in the study of hepatic ailments. A review of the literture revealed few previous publications concerning the differential features of the two conditions although some characteristic scan findings of each condition have been described. The present study is aimed at a critical review and analysis of various photoscan findings and blood disappearance rate determinations of colloidal 198Au of 34 cases of primary hepatoma and 30 cases of amebic liver abscess. Among many scan manifestations, prominence of the uninvolved liver tissue, "hemispherical cold area," and splenic uptake are much more commonly encountered in primary hepatoma and the blood disappearance rate tends to be far more frequently delayed in primary hepatoma than in abscess providing at least a statistically useful basis of distinction of the two diseases.