Copper T intrauterine devices (IUDs) are a popular long-acting reversible contraceptive method. The most common reasons for contraceptive failure are expulsion and extrauterine migration. We report a case of a 28-year-old female, G13P3, 37 weeks pregnant, who presented to the hospital for left abdominal flank pain. The patient was admitted for treatment of left ureteral colic. The woman went into labour, and Caesarean Section was performed due to foetal distress. During the surgery, an inspection of the peritoneal cavity revealed a copper IUD embedded in the granulous tissue located in the left lateral abdominal region, which was extracted. No uterine scar tissue could be identified macroscopically. The migration of an IUD in the abdominal cavity is a rare finding, and coexistence with third-trimester pregnancy is an infrequent but serious event due to potential visceral complications. Higher gravidity can be associated with an increased risk of IUD migration in women with a non-scarred uterus.