This report presents two cases of young males who developed the rare idiopathic form of sclerosing encapsulating peritonitis (SEP) presented as partial bowel obstruction, both diagnosed during surgical treatment, with satisfactory outcomes. Sclerosing encapsulating peritonitis is a rare and enigmatic condition, characterized by intraperitoneal fibrosclerosis, which causes intestinal obstruction. It is a chronic entity with a poorly elucidated pathophysiology, leading to the constitution of a thick white nacreous fibrosis membrane that wraps the bowel in a concertina-like fashion with some adhesions configuring an intra-abdominal cocoon. Sclerosing encapsulating peritonitis is reported in a wide variety of patients, including those who have undergone peritoneal dialysis, young adolescent girls, cirrhotic patients after peritoneal-venous shunting, and patients treated with β-blockers. Nevertheless, the etiology of SEP remains obscure. This entity presents many difficulties in preoperative diagnosis because of its peculiar characteristics. Recognition of the SEP results in proper management and prevents unnecessary bowel resection. Regardless of cause, the treatment of the obstruction is surgical, with dissection of the encasing membrane from the intestine and separation of adherent loops of small bowel until they are laid free and returned to their normal configuration. The prognosis after appropriate surgical therapy is good, but depends on coexisting diseases.