Hepatoid adenocarcinoma is a type of cancer with both adenocarcinomatous and hepatocellular differentiation. Hepatoid adenocarcinoma has a typical character of high serum alpha-fetoprotein (AFP) level. A 61-year-old female patient was admitted to the hospital with abdominal pain and hepatic mass. Abdominal ultrasonography revealed a 20 cm sized mass in liver. A huge hepatic mass looked like primary hepatocellular carcinoma (HCC) on liver CT and MRI. Also, serum AFP was elevated to 24215.7 ng/mL. Right trisectionectomy was done under the impression of HCC. However, the result of pathological findings including immunohistochemical staining revealed that it was a hepatoid adenocarcinoma which was originated from gallbladder