Technetium-99m galactosyl human serum albumin (TcGSA) is a synthesized radiolabeled analog ligand to asialoglycoprotein receptor, which resides only at a mammalian hepatocyte. TcGSA studies were performed on 16 patients with various acute liver disease and 3 controls with normal livers. Dynamic data were obtained by a gamma camera during 35 minutes after an intravenous injection of 3 mg (185 MBq) of TcGSA. The parameters of TcGSA time activity curves were obtained by dividing radioactivity of the liver by that of the liver plus heart at 15 min (Receptor Index), and by dividing radioactivity of the liver at 15 min by that at 3 min post injection (Clearance Index). The two parameters correlated well with prothrombin time, clinically estimated staging, and severity of acute liver disease. We have concluded that liver function study by the newly developed receptor imaging with TcGSA can be a sensitive and promising tool in estimating the severity and prognosis of acute liver disease.