Primary benign mesodermal tumors of the liver fare relatively rare. Especially, primary hepatic leiomyoma is very uncommon. The authors present a case of hepatic leiomyoma in 42 years old woman, who was admitted to Catholic Medical Center, because of abdominal distension for 3 months. Abdominal computerized tomography revealed a tennis ball sized spherical mass on right lobe of the liver. On operation, this mass, although it adhered to the diaphram, was well defined, so a right hepatic lobectomy was performed. Any abnormalities did not found in the internal organ. On gross examination, there was a tumor mass on the dome of the right lobe of the liver, which was covered with hepatic capsule. On cut section, it was well defined, and revealed whitish-gray coarse cut surface with focal hyaline degeneration. Hemorrhagic or necrotic areas were not found. Microscopically, the tumor was composed of chiefly smooth muscle cells interposed some fibrous tissue. Although the tumor revealed relative hypercellur areas, any abnormal mitotic figure was not detected. This case is presumable fourth case of primary hepatic leiomyoma in the literatures.