<p>The intrauterine device (IUD) is an important and highly effective means of contraception. Migration of the IUD, post implantation, out of the uterus is an infrequent complication, and an IUD partially perforating the bladder is even more infrequently reported. The authors report a 44-year-old woman who had a copper-M IUD inserted into her uterus 16 years ago. Six months later an unexpected pregnancy occurred and an elective suction abortion was performed without ultrasound check before or after surgery. A copper-T IUD was inserted immediately after completion of the abortion but she was subsequently lost to follow-up. Before detection of the ectopic state of the IUD, she complained of lower quadrant abdominal pain following urination for one month. Physical examination revealed mild tenderness upon deep palpation of the suprapubic area. A series of imaging studies had been performed to confirm the exact position of the ectopic IUD. Transabdominal ultrasound showed a linear hyperechoic foreign body embedded in the right side of the bladder wall, a plain abdominal X-ray showed an M-shaped IUD on the right side of the pelvis, an abdominal CT scan found a portion of one arm penetrated the right anterior bladder wall, and nephroscopy demonstrated a one-centimeter of penetration depth and surrounding calculus formation. The IUD arm was gently pulled into the bladder with forceps and was subsequently removed through the urethra. A Foley catheter was later placed into the bladder for one week to manage the bladder perforation. The patient made an uneventful recovery.</p><p><?noindent??>This case demonstrates that partial bladder perforation with the IUD body outside the bladder can be successfully managed via transurethral nephroscopy. A stepwise imaging strategy (ultrasound → KUB → CT) is essential for surgical planning. We propose a treatment-oriented classification and a replicable clinical pathway integrating multidisciplinary collaboration and tailored technology selection.</p>