Malignant primary peritoneal tumors are rare and should be kept in mind when peritoneal carcinomatosis is diagnosed without primary tumor found. The principal etiologies are peritoneal mesthelioma, pseudomyxoma peritonei and primary peritoneal serous carcinoma. Their diagnosis requires most of the time biopsy performing by laparoscopy that should prevent tumoral parietal diffusion (port sites on the middle line). The treatment of reference combines optimal cytoreductive surgery and perioperative intraperitoneal chemotherapy when general status allows performing it. The management of these diseases should be done into specialized centers, included into national network (RENAPE), because of specificity and complexicity of treatments and to facilitate clinical and fundamental research on rare disease.