Partial or total encapsulation of bowel in a membrane-like sac is a rare cause of mechanical bowel obstruction. Three different types of encapsulation have been described: a congenital, a secondary and an idiopathic or "abdominal cocoon". The present case describes a 34-year-old male, who was admitted with small bowel obstruction caused by an "abdominal cocoon", which was successfully treated by surgery. Precise preoperative diagnosis is often missed, but a computed tomography visualizing bowel loops enclosed in a membrane is a characteristic finding.