The relationship of technetium-99m(Sn)-N-pyridoxyl-5-methyltryptophan (99mTc-PMT) uptake by hepatic tumors to survival was studied in 162 cases of hepatocellular carcinoma (HCC). The median survival of 82 patients in whom hepatic tumors showed increased uptake in delayed 99mTc-PMT imaging was 1013 days, which was significantly longer than the survival time of 398.5 days of 80 patients in whom hepatic tumors did not show increased uptake of radioactivity (p less than 0.002). The relationship between the ability of hepatic tumors to take up 99mTc-PMT and survival was also analyzed in patients with HCC showing filling defects in 99mTc-colloid liver images and, in relation to the therapy, serum values of bilirubin and alpha-fetoprotein. Results indicated that the degree of 99mTc-PMT uptake by hepatic tumors is closely correlated with the prognosis of patients with HCC.