We report the MR imaging findings of a primary malignant mesothelioma of the liver arising from Glisson's capsule. A 54-year-old woman, presenting with acute abdominal pain and a large liver mass previously shown on CT, underwent MR imaging to characterize the lesion. The tumor was a greater than 12 cm tumor located in the right lobe of the liver, which was sharply marginated, with heterogeneous internal signal, septations and central necrosis. The tumor was considered a hepatocellular carcinoma. The diagnosis of malignant mesothelioma was established by immunohistochemical staining and electron microscopy of the resected tumor.