A pregnant patient presented to the emergency-room with macrohematuria, and flank pain caused by a right lumbar ureter stone. Despite medical therapy, persistent macrohematuria and pain prompted the placement of a DJ stent and a catheter nephrostomy, but hemoglobin levels continued to decrease. Doppler ultrasound revealed a arteriovenous fistula. Following an initial conservative approach, the patient underwent fistula embolization, resulting in the successful closure of the fistula. The patient remained stable, and after 70 days, the baby was born. This case highlights the rare occurrence of arteriovenous fistula during pregnancy and the importance