Primary papillary carcinosis of the peritoneum is a rare disease seen in elderly women in whom no digestive or ovarian carcinoma could be detected. Its histological structure is identical with that of papillary carcinoma of the ovary. The 4 cases reported here were treated as advanced ovarian carcinomas, with multiple chemotherapy including doxorubicin and cis-platinum. Three patients were re-operated upon after 6 courses. Complete remission was obtained in all 4 cases, but the patients relapsed under maintenance therapy. The diagnosis must be suspected in elderly women presenting with unexplained carcinosis. This is particularly important since effective treatments can now be proposed, as for advanced ovarian carcinomas.