Inguinal hernias are common diseases, but malignant lesions in groin hernias are rare; metastatic hepatocellular carcinoma (HCC) in the hernia sac is extremely rare. We report a 72‐year‐old man who had advanced stage HCC with portal vein invasion and multiple metastatic lymphadenopathies. He presented a painless palpable mass in the right groin. Computed tomography scan showed a contrast‐enhanced soft tissue mass (2.8 cm in size) at the right herniated inguinal sac. Tumor excision and hernia repair were performed, and the histopathological examination revealed metastatic HCC. After being stabilized from surgery, the patient received combination therapy with sorafenib and nivolumab; however, he still died of rapid tumor progression and liver decompensation 1 month later. This case raises clinical awareness of unusual extrahepatic metastases of HCC, especially for patients at an advanced tumor stage.