Ovarian cancer is usually diagnosed at an advanced stage with peritoneal extension which often occurs early on. Imaging plays an important role in the pretherapeutic assessment of peritoneal extension. Carcinomatosis involving the hepatic hilum, the cavo-supra-hepatic confluence, the mesentery, and/or the intestinal wall precludes optimal surgery and may be an indication for neoadjuvant chemotherapy. Abdominal and pelvic MDCT scan is the best imaging technique for the preoperative staging of peritoneal carcinomatosis. MRI can be useful in some cases. Conventional imaging however sometimes underestimates peritoneal carcinomatosis and therefore cannot always be a substitute for surgical staging.