Patients with peritoneal mesothelioma present with abdominal distension and clinical syndrome of debilitating ascites. Cytology of the peritoneal fluid obtained by laparocentesis often does not result in a diagnosis. Laparoscopy with biopsy of peritoneal nodules is a valuable method by which a histological diagnosis is established. However laparoscopy can greatly complicate the management of peritoneal mesothelioma by facilitating tumor dissemination to port sites. The patient presented was treated with cytoreductive surgery and perioperative intraperitoneal chemotherapy. Although palliation of intra-abdominal tumor and ascites was achieved, port sites-disease required extensive resection of the abdominal wall. Our experience with this patient suggests that if a malignant source of ascites is suspected and a diagnosis is not obtained by paracentesis, laparoscopy should be used to establish a diagnosis. However, trocars should only be placed along the midline of the abdominal wall so that port sites can be excised at the time of cytoreductive surgery. This diagnostic strategy is applicable to the majority of patients undergoing laparoscopy when there is known or suspected intraabdominal malignancy.