Opisthorchiasis is a relatively common disease in the northeast of Thailand. Fifteen cases were studied by CT, revealing interesting findings: 1. Fourteen cases had abnormal liver CT. 2. Dilatation of intrahepatic biliary tree was very common, in various degrees. 3. Most patients had co-existing cholangiocarcinoma, some with peritoneal seeding and/or regional lymph node involvement. Metastases to pancreas, adrenal gland, spleen, lung and pleura are occasionally seen at initial diagnosis. CT findings are very suggestive of this disease. However, diagnosis depends on history, clinical and parasitological bases.