A 70-year-old woman was admitted to our hospital complaining of epigastralgia. Computed tomography, ultrasonography and magnetic resonance imaging revealed a round tumor measuring 6 cm in diameter, which was located in the medial side of the right kidney. It was successfully removed without injury to the surrounding large vessels and organs. Histological diagnosis was benign neurofibroma. This is the 27th case of solitary retroperitoneal neurofibroma reported in Japan.