BackgroundA wide variety of complications due to the extrauterine migration of intrauterine contraceptive devices have been reported in the literature. Here we describe the case of a large bladder stone formed around a migrated Copper T380A device that was neglected and detected 15 years after insertion.Case presentationA 48-year-old Sri Lankan woman underwent a workup for lower urinary tract symptoms and recurrent urinary tract infections over the previous 6 months. The radiographs showed a large bladder stone with an imprint of an intrauterine contraceptive device in the center of it. The device had been inserted 15 years previously. Two years after the insertion, it was considered to be missing, but our patient did not comply with the recommended follow-up. She had been completely asymptomatic until she developed lower urinary tract symptoms. After confirming the location of the stone via ultrasonography, a vesicolithotomy was performed, revealing a stone with three limbs corresponding to the shape of the Copper T380A device. The device and the threads were fully covered with the stone material. Our patient was asymptomatic following the surgery.ConclusionsA migrated intrauterine contraceptive device can act as the nidus for the formation of a secondary bladder stone. The detailed imprint of the device inside the stone and the laminated appearance of the stone material were characteristic of a secondary bladder stone formed around an intrauterine contraceptive device. Radiography and ultrasonography are adequate for the diagnosis of intravesical migration of intrauterine contraceptive devices.