Bengn solitary neurilemmoma of the retroperitoneum is a rare disease of nerve sheath origin. A 40-year-old male patient was admitted to our hospital for evaluation of retroperitoneal mass. Abdominal ultrasonography and computed tomogaphy (CT) revealed a solid tumo in the retroperitoneum. On exploratory laparatomy, this mass turned out to be an baseball sized mass of the retroperitoneum. The mass was excised surgically in an encapsulated state. Histological section and immunohistochemical stain revealed a typical neurilemmoma. We report it with a review of literature.