We treated a 66-year-old woman with hepatic encephalopathy secondarily induced by an intrahepatic portosystemic venous shunt (IPSVS). In serial observations, the volume of the liver became smaller and encephalopathy could not be controlled with conservative therapy. We occluded the IPSVS successfully using percutaneous transcatheter embolization with micro coils. Following embolization, encephalopathy disappeared and blood flow of all branches of portal vein improved. In cases with an IPSVS without liver cirrhosis, blood flow in the portal vein and liver volume must be followed carefully, and interventional radiology may be considered effective in those who do not show a satisfactory response to conservative therapy.