Zinner's syndrome is a rare congenital disorder presenting with unilateral renal agenesis or dysgenesis, ipsilateral seminal vesicle cysts, and ejaculatory duct obstruction. Treatment of this syndrome can be conservative or surgical. In this case report, we describe the case of a 72-year-old patient who was diagnosed with Zinner's syndrome and underwent laparoscopic radical prostatectomy for prostate cancer treatment. The peculiarity of our case was that the patient's ureter emptied ectopically into the left seminal vesicle, which was notably enlarged and multicystic in appearance. Although many minimally invasive procedures have been reported for treating symptomatic Zinner's syndrome, to our knowledge, this is the first reported case of prostate cancer in a patient with Zinner's syndrome who was treated with laparoscopic radical prostatectomy. Laparoscopic radical prostatectomy can be safely and efficiently performed in patients with Zinner's syndrome and synchronous prostate cancer by urological surgeons with extensive experience in laparoscopy in high-volume centers.