Background: Abnormalities of mesonephric ducts are rare congenital conditions, which can present with vague symptoms in otherwise healthy men. Zinner's syndrome is the association of an enlarged seminal vesicle cyst with ipsilateral renal agenesis, which can be symptomatic and require operative interventions. Case: We present the case of an otherwise healthy 24-year-old man who presented with a symptomatic 15 cm seminal vesicle cyst, which was completely excised using a robot-assisted approach. Conclusion: Use of robotic surgery for excision of large seminal vesicle cysts is a safe and effective operative procedure.