Peritoneal carcinomatosis is a common event that develops in the natural history of many neoplastic diseases, representing a major problem encountered in cancer, management. Peritoneal seedings are often associated with neoplastic ascites resulting in a source of significant discomfort to the patient. Considered in the past as a terminal condition, peritoneal carcinomatosis was approached during the last two decades as a curable disease. The introduction of cytoreductive surgery or peritonectomy in the treatment of peritoneal neoplastic diseases drastically changed the natural history of peritoneal carcinomatosis. Another technique that showed an important impact on disease control is intraperitoneal hyperthermic perfusion, one of the most fascinating treatments of peritoneal carcinomatosis that results in an impressive increase in overall survival and quality of life in treated patients with low morbidity. This review illustrates the modality of dissemination of peritoneal carcinomatosis in relation to the primary tumor site and grade of malignancy. Peritoneal carcinomatosis is a term used to define an advanced stage of many abdominal neoplastic diseases that differ in biologic aggressiveness and prognosis. The different presentation of peritoneal carcinomatosis in relation to a different primary tumor and different grade of malignancy strongly influences the potentially therapeutic radical approaches using new and advanced modalities like cytoreductive surgery and intraperitoneal hyperthermic perfusion.