Pseudomyxoma peritonei is a clinical entity in which peritoneal surface and omentum are diffusely involved with gelatinous mucinous impalants and gelatinous ascites is massive. Before the advent of CT of the body, the radiographic findings of pseudomyxoma peritonei were elusive and extremely nonspecific. Authors reviewed the CT findings of 8 cases of pseudomycoma peritonei to assess the diagnostic value of CT, and the results were asfollows: 1. The CT findings of pseudomyxoma peritionei are a) massive ascites with slightly high density(20-40HU),(8/8 cases ) b) loculated intraperitoneal fluid with surrounding daughter cysts,(6/8 cases ) c) scalloping of theliver margin,(3/8 cases). d) scalloping or indentation of bowel wall with pleomorphic abdominal mass,(4/8 cases).e) extensive tumor infiltration of the omentum,(5/8 cases). 2. CT could detect the primary sites of pseudomyxomaperitonei in six of eight cases. 3. In all cases, we could assess the disease extent on CT by detction of gelatinous material at variable sites from the lower pelvic cavity up to the upper abdomen. We believe that CT will prove itself a very accurate method of diagnosing advanced pseudomyxoma peritonei, and detection of primary site and extenstion of pseudomyxoma peritonei.