Peritoneal mesothelioma is a rare, either benign or malignant tumor of the peritoneum. We retrospectively analyzed the imaging features of six malignant and three benign peritoneal mesothelioma. Asbestos exposure was proven in three of the six malignant cases and in none of the three benign cases. Ascites was found in seven patients (78%), peritoneal masses in eight patients (88%), small peritoneal nodules in six patients (66%), parietal peritoneal thickening in six patients (66%), thickened mesentery in five patients (55%) and pleural plaques as well as nodules in one patient. These imaging features support the diagnosis of peritoneal mesothelioma but do not allow differentiation between benign and malignant forms of peritoneal mesothelioma.