<p>Hydatid disease, caused by the larval stage of Echinococcus granulosus, primarily affects the liver and lungs. Genitourinary involvement is infrequent (2–4%), with the kidneys being the most commonly affected organs. Primary hydatid cysts of the urinary bladder are exceedingly rare. These cysts may remain asymptomatic or mimic other urological conditions such as bladder stones or malignancy, especially when presenting with lower urinary tract symptoms (LUTS). We report a case of a 70-year-old male presenting with LUTS and urine leakage through a previous surgical scar, initially suspected to be a vesico-cutaneous fistula. Imaging demonstrated a large calcified cystic lesion within the bladder cavity with bilateral hydroureteronephrosis. Bilateral percutaneous nephrostomies were performed for decompression, and albendazole therapy was initiated. Following normalization of renal function, open surgical excision of the cyst and fistula repair were performed. The postoperative course was uneventful, and bladder healing was confirmed by cystography at three weeks. Histopathology revealed a hydatid cyst with laminated, calcified walls and chronic inflammation in the fistulous tract. This case highlights the diagnostic challenge of primary bladder hydatid cyst. It emphasizes the need for high clinical suspicion, appropriate imaging, and complete surgical excision without rupture to ensure definitive management and prevent recurrence.</p>