Sequential 2 min scintiphotos were obtained with a scintilation camera after intravenous injection of 3mCi of (99m)Tc-HIDA or (99m)Tc-PI. Digital matrix images were simultaneously recorded with computer. Sequential samples for the blood clearance of (99m)Tc-HIDA or (99m)Tc-PI were obtained for 120 min following injection to the patient of constitutional hyperbilirubinemia and ICG excretory defect disease. In Dubin-Johnson syndrome, the hepatic uptake of (99m)Tc-HIDA was faster or normal but the excretion was extremely slower than in normal cases. Both hepatic uptake and excretion of (99m)Tc-PI were almost normal. In Rotor's disease, hepatic uptake of (99m)Tc-HIDA or (99m)Tc-PI was very poor, showing almost no hepatic images in all time. In Gilbert's disease and ICG excretory defect disease, hepatic uptake and excretion of (99m)Tc-HIDA or (99m)Tc-PI were within normal limit. From these results, Dubin-Johnson syndrome, Rotor's disease and Gilbert's disease show the different patterns between hepatic uptake and excretion of (99m)Tc-HIDA and (99m)Tc-PI hepatobiliary scintigraphy and these patterns contribute to the differential diagnosis of constitutional jaundice. The usefulness of hepatobiliary imaging with (99m)Tc-EHIDA in diagnosis of hepatocellular carcinoma was studied in 15 patients with histologically verified HCC. In 15 patients, 3 patients (20%) showed increased radioactivity with (99m)Tc-EHIDA image, where liver scan with (99m)Tc-Sn colloid showed filling defect. These results indicate that use of (99m)Tc-EHIDA scan and (67)Ga-citrate imaging is useful for positive visualization of HCC.