Background. Abdominal cocoon, or sclerosing encapsulating peritonitis, is a rare condition characterized by partial or total encasement of small bowel and mesentery by a thick fibrocollagenous sack that looks like a cocoon. Within the sack, bowel loops are drawn together causing intestinal obstruction.Case presentation. We report on a 57-year-old female patient who developed a very unusual complication of ovarian cancer: abdominal cocoon formation.Conclusions. This report highlights the need for a timely diagnosis of sclerosing encapsulating peritonitis in cancer patients.