Background: In Zinner syndrome (ZS), surgical intervention is recommended for pediatric patients with symptomatic disease. It is generally believed that cyst aspiration alone may lead to symptom recurrence. Although comprehensive surgical excision is often advocated to prevent recurrence, a combined approach of cyst aspiration and maximal cyst wall ablation may also provide lasting symptom relief. Case Presentation: A 14-year-old boy with a long-standing history of voiding difficulties presented with acute urinary retention. Pelvic magnetic resonance imaging revealed a 5 cm × 4 cm × 3.5 cm cystic lesion arising from the right posteroinferior prostate and compressing the bladder. Transurethral laser ablation of the ejaculatory duct cyst was performed using a holmium:YAG laser (0.8 J, 10 Hz). The patient recovered uneventfully and was discharged on postoperative Day 1. At the 1-year follow-up, he remained asymptomatic with normal uroflowmetry findings and only a small residual cyst visible on ultrasound. Conclusion: For the management of large seminal vesicle cysts in ZS, combining cyst aspiration with cyst wall ablation provides an effective, safe, and durable therapeutic approach.