INTRODUCTION An intrauterine contraceptive device (IUCD) is a common contraception method used for family planning. IUCD erosion into adjacent organs is a rare but serious complication of IUCD use. CASE PRESENTATION A 41-year-old female presented to us with a leaking left ectopic pregnancy. Emergency laparotomy and left salpingectomy were performed. A copper ICUD was found intraperitoneally and part of it had completely eroded into the sigmoid colon. Sigmoid colotomy was performed and the IUCD was removed successfully. Further history revealed that the patient had her IUCD inserted 12 years previously but was forgotten. The patient was discharged well after 4 days of admission. DISCUSSION Erosion of an IUCD into the colon is uncommon and may be asymptomatic or present with bowel perforation and obstruction. There should be a high index of suspicion for pregnancy occurring among women post-IUCD insertion. A misplaced IUCD can cause chronic inflammation of the fallopian tube, which may alter tubal functionality and increase the risk of ectopic pregnancy. Family planning is commonly done in primary health care. Primary care education and counselling are essential to improve awareness of fertile women to prevent similar complications. Periodic examination of IUCD string either by users or primary health-care practitioners is crucial. Ultrasound can be advocated if there are difficulties with the insertion. An abdominal radiograph is useful and should be performed in the case of missing IUCDs.