Diffuse liver hemangiomatosis with giant cavernous hemangioma in adult is extremely rare. A 35 year-old woman presented to hospital with main complaint of epigastric pain and abdominal fullness. An enhanced computed tomography scan revealed a massive liver tumor in right lobe about 150 mm in size. There was contrast enhancement at the periphery of the mass consistent with a cavernous hemangioma. She underwent right hepatectomy. Histologically, it was diagnosed as a cavernous hemangioma. And also, hemangiomatous lesions were scattered around the Glisson's capsule on the back ground liver. These hemangiomatous lesions were not recognized preoperatively. Even if we couldn't diagnose hemangiomatosis around the main giant hemangioma preoperatively, we need to take enough surgical margins because the giant hemangioma has the potential to have small hemangiomatous lesions around the tumor. We reported right hepatectomy for giant cavernous hemangioma with diffuse hepatic hemangiomatosis without an extrahepatic lesion in an adult.