A captive 5-yr-old castrated male Rocky Mountain wapiti (Cervus elaphus nelsoni) developed stranguria. Rectal palpation and physical examination indicated urethral obstruction that was subsequently relieved by urethrostomy and required only minimal aftercare. The wapiti was able to urinate freely after surgery; however, the obstruction recurred 27 mo later. Urethral catheterization relieved the second obstruction, which was caused by a large calculus composed of calcium carbonate and magnesium carbonate. Urolithiasis may have been associated with a diet high in calcium, and urethral obstruction may have been associated with castration at an early age. The wapiti continued to urinate freely 9 mo after relief of the second obstruction and 3 yr after the initial surgery.