Benign tumors of the Seminal vesicle that occur more commonly then malignant tumors. Cystadenoma is an extremely rare benign tumor of the seminal vesicle. Management of these tumors remains debatable due to the limited data in the literature. We present a cystadenoma of the seminal vesicle was resected using an open transvesical approach. A Sonography reported enlarged prostate with volume of 560 ml with multiple cystic area inside it. CT scan and abdomen and pelvic MRI with and without Gadolinium also performed and huge (120 * 100 * 100mm) heterogeneous mass in anatomic site of prostate reported. Patient underwent pelvic mass resection by retro vesical abdominal approach. Final pathology report is consistent with cystadenoma/epithelial stromal tumor of the seminal vesicle with no suggestion for malignancy. After recovery from surgery patient was symptom free and totally continent with preserved erectile function. Surgical intervention may be considered when a cystadenoma of the seminal vesicle is diagnosed and symptoms or tumor growth occurs transvesical removal of seminal vesicle mass is an effective surgical procedure for seminal vesicle disease.