Primary malignant peritoneal mesothelioma. A report of seven cases and a review of the literature. Mesothelioma of the peritoneum is a rare malignant neoplasm easily mistaken by both surgeon and pathologist for one of the more common neoplasms of the abdomen. Review of our records from metropolitan-area hospitals for the past 15 years identified seven patients with primary peritoneal mesotheliomas. Their diagnosis, management, and survival is analyzed. We report a case of an extended survivor (7 years) and one of a long-term survivor (15 years), as well as what we believe to be the only case in the literature presenting with a coexistent malignant neoplasm. Prevention of this commonly fatal neoplasm is linked to avoiding occupational exposure to asbestos; long-term survival for a few patients may be achieved with correct identification of the neoplasm and aggressive management. This report includes a review of the literature. 