Primary hepatic actinomycosis is relatively rare, but it should be remembered in the differential diagnosis of liver masses. A 66-year-old woman with right hypochondralgia was admitted and for detailed examination and treatment of a liver tumor. Abdominal ultrasonography revealed a hypoechoic lesion 55 mm in diameter in the anterior segment. Enhanced CT showed a deep-stained tumor in the early phase and a low density area in the late phase. The feeding arteries were the right hepatic artery and right inferior phrenic artery on abdominal angiography. The patient was given a diagnosis of hepatocellular carcinoma with invasion of the inferior lobe of the right lung. We performed a central bisegmentectomy of the liver and partial resection of the inferior lobe of the right lung. Microscopic findings of the resected specimen revealed sulfur granules and the tumor was diagnosed as primary hepatic actinomycosis.