Portal biliopathy is a morphological abnormality of the biliary ductal and gallbladder wall associated with portal hypertension. A patient with essential thrombocythemia was initially diagnosed with extrahepatic portal vein obstruction (EHPVO). The contrast-enhanced computed tomography (CT) findings were similar to those of cholangiocarcinoma or sclerosing cholangitis. However, color Doppler and contrast-enhanced ultrasound (US) were more specific. The paracholedocheal veins around the bile ducts appeared as beads soon after the injection of contrast medium, followed by linear enhancement of the epicholedochal veins and the gradual enhancement of the whole bile ducts. These findings led to a diagnosis of portal biliopathy, which prevented the patient from having to endure hazardous procedures such as bile duct biopsies. Color Doppler and contrast-enhanced US findings are useful for diagnosing or ruling out portal biliopathy in patients who present with EHPVO.