Primary hepatic leiomyoma (PHL) is a rare benign tumor, with only 36 cases reported in the international literature, and its pathogenesis is not clear. Here we report a rare case of PHL diagnosed with coexisting gastric cancer. An asymptomatic, 57-year-old man without any significant medical history was referred to our hospital because of early gastric cancer and a hepatic mass. His physical examination was unremarkable. The laboratory tests and tumor markers, including alpha fetoprotein, CA 19-9, and carcinoembryonic antigen, were within the normal range. Viral hepatitis serology was negative. Computed tomography revealed the hepatic mass was 33 mm in size in segment II of the liver. He underwent a US-guided needle biopsy, but we could not obtain a biopsy specimen, as the firmness of the liver mass made it impossible to put the needle through into the core. Hence, he underwent a diagnostic laparoscopic wedge resection. The mass was histologically typical for a leiomyoma.