Three pathologically proven cases of malignant peritoneal mesothelioma (MPM) are shown with markedly different computed tomographic (CT) appearances. The first presented as a large enhancing pancreatic mass, a second with diffuse solid large intraperitoneal masses enveloping bowel and mesentery, and a third with predominance of ascites and small peritoneal nodules. In only one patient was there a history of possible asbestos exposure. The CT findings, pathology, and differential diagnosis of MPM are discussed.