A 55 year-old man was admitted with massive ascites. Although the laboratory data on admission were compatible with hepatic cirrhosis and remarkable esophageal varices were observed during endoscopy, the imaging findings such as computed tomography and ultrasonographic examination did not confirm hepatic cirrhosis. The patient had no history of alcohol abuse, blood transfusions or acute hepatitis. Serological markers related to viral and autoimmune hepatitis were all negative. Seven years ago, the patient had undergone an operation for colon cancer and has been taking tegafur since then for a total of 55 months. Tegafur was suspected as the causative agent for the liver dysfunction of this patient and the administration of tegafur was stopped. His laboratory data improved gradually and the ascites vanished. The first liver biopsy performed 6 months after discontinuation of tegafur still revealed chronic active hepatitis. However, at the liver biopsy performed 18 months after withdrawal of tegafur, inflammatory activity had subsided and the third liver biopsy, performed 34 months thereafter, revealed further improvement of the pathological changes that had occurred in the liver. We therefore conclude that the administration of tegafur may have caused chronic active liver injury with portal hypertension manifested as ascites and esophageal varices.