The peritoneal carcinomatosis is considered an unlikely treatable disease using standard procedures as surgery or systemic chemotherapy. New improvements in the knowledge of the peritoneum are inducing to consider the mesothelium of the abdominal cavity as an organ similar to the other body organs. This new consideration, unified with the understanding of conditions permitting the implant of the tumor cell into the peritoneal space previous or during the surgical manipulation of the abdominal cancers, leads to the application of news strategies as the advanced cytoreduction with every nodes reduced less than 2.5 mm followed by the chemohyperthermic peritoneal perfusion (CHPP). Last papers indicate improvements in overall survival and quality of the life in ovarian, colonic and gastric cancer treated with an extensive surgical debulking plus CHPP. These results induce surgeons and oncologists to avoid incorrect strategies in the treatment of peritoneal carcinomatosis originating from ovarian and gastrointestinal tumors. In case of malignant untreatable ascites a peritoneo-venous shunt allows a control of the ascites avoiding several hospital admissions for continuous fastidious and sometime dangerous paracentesis. A palliative surgical operation in selected patients effected by trained surgical group permits an improvement of the patient's conditions in more than 80% with a positive feed back on his or her psychological behavior.