Sclerosing encapsulating peritonitis is a very rare pathological entity. It is a chronic fibroinflammatory disease affecting the peritoneum and leading to the formation of diffuse egg-shell-shaped fibrous capsule which totally or locally encapsulate the abdominal viscera, in particular the digestive tract. Clinical signs are little specific and misleading. Medical imaging, including computed tomography, can help clinicians to make a diagnosis, by highlighting a thin peritoneal membrane encompassing an agglutination of digestive loops. Secondary types (postperitoneal dialysis, tuberculosis, medications, postintraperitoneal chemotherapy) are quite common, however idiopathic sclerosing encapsulating peritonitis is very rare and few cases have been reported in the literature. We here report the case of a 53-year-old woman with idiopathic sclerosing encapsulating peritonitis.