The incidence of transuterine perforation and migration of intrauterine contraceptive devices (IUCDs) into the abdominal cavity has been estimated at less than 0.1%. It has been suggested that intraperitoneal IUCD have low morbidity and may be left in situ. We report the first case of closed loop small bowel obstruction due to migration of a "Saf-T-Coil" IUCD into the abdominal cavity, where it became embedded in the omentum and ultimately, 31 years after deployment, coiled both arms around a loop of ileum. This late complication underlines the dangers of intra-abdominal foreign bodies, even when chemically and biologically inert.