Ectopic hepatocellular carcinoma (HCC) is a rare malignancy, which manifests similar morphology and immunohistochemistry to intrahepatic HCC. Herein, we report a case of ectopic HCC in a 73-year-old male. The patient presented to our hospital with gradually progressing right lower abdominal pain, and enhanced computed tomography revealed multiple nodules in the peritoneum without intrahepatic mass. A diagnostic laparoscopy was performed, and the final pathology result confirmed that it was HCC. Additional laboratory tests showed elevated serum alpha-fetoprotein and protein induced by vitamin K absence-II (PIVKA-II) levels, suggesting our diagnosis. The patient received sorafenib, a tyrosine kinase inhibitor (TKI), for unresectable ectopic HCC. However, the tumor progressed, and because of tarry stools and hemorrhagic anemia, sorafenib was ceased after 7 months of therapy. One month after the cessation of sorafenib, the PIVKA-II level increased abruptly, and the patient died 1 year after diagnosis. The effective treatment for unresectable ectopic HCC is still unknown. Additional cases should be accumulated to determine the effect of TKI on ectopic HCC.