Clod areas in scintiphotoscan of amebic abscess, pyogenic abscess, hepatoma and metastatic carcinomata look all alike without distingushing features. But since the hepatic blood flow, which can be estimated by simple external counting of disappearing radioactivity from peripheral blood of colloidarl sup 198Au varies according to the type of disease, the combination of both tests may augment diagnostic specificity. We studied retrospectively 53 cases of amebic abscess, 15 cases of pyogenic abscess, 59 cases of hepatoma and 28 cases of metastatic carcinomata from various primary sites. The present study revealed that blood clearance rates were accelerated in 41.5% of patients with amebic abscess and in 46.4% of those with metastatic carcinomata, whereas clearance rates were delayed in 76.3% of patients with hepatoma. The clearance rates remained unchanged in those with pyogenic abscess. It emerges, therefore, that when a cold area is found in connection with an accelerated blood clearance rate then it is quite likely that the cold area represents either amebic abscess or metastatic carcinomata. The reverse holds in hepatoma. No change in clearance rates should raise the possibility of a pyogenic abscess.