Book excerpt: Ovarian cancer is the most common cause of death among all gynecological neoplasms. Ovarian epithelial cancer represents approximately 90% of all ovarian malignant tumours. The most usual pattern of spread and probably the earliest kind of metastasis of ovarian cancer is intraperitoneal spread, caused by apoptosis of viable cancer cells, even in cases where the ovarian surface has no visible rupture. Approximately 70% to 75% of all ovarian cancers are being diagnosed with peritoneal carcinomatosis and ascites in advanced stages III and IV. Peritoneal carcinomatosis from ovarian cancer may occur either concomitantly with the primary tumour or as a recurrence pattern of spread. Standard treatment consists of surgical debulking and postoperative systemic chemotherapy. Response rates to first-line chemotherapy with platinum/taxane combinations are high, about 70-80%, but the vast majority of patients will relapse. Peritoneal seeding is a major cause of surgical treatment failure among those patients, even after optimal debulking. However, progressing ovarian cancer tends to remain within the peritoneal cavity or, better-expressed, ovarian cancer is a cancer of the peritoneum. The administration of cytotoxic agents directly into the peritoneal cavity as treatment for malignancy was initially evaluated more than 40 years ago. Over the past two decades regional therapy of ovarian cancer has evolved from just an interesting pharmacokinetic concept into a viable management option for women with advanced disease. Several authors, and among them some of the world's leading experts on this field present the current knowledge and their experience on peritoneal carcinomatosis from ovarian cancer.