The aim of this study was to describe the radiological appearance of retroperitoneal ganglioneuroma. We retrospectively reviewed seven cases of histologically proven retroperitoneal ganglioneuroma. Ultrasound and enhanced CT were obtained in all cases, and MRI in three cases. The masses were well-circumscribed, ranged in size from 5 x 3 x 3 to 10 x 6 x 4 cm. In three cases close relationships between the tumor mass and major blood vessels were noted, resulting in vessel displacement or surrounding, but without compression or occlusion. On ultrasound examination the tumor showed a heterogeneous solid echostructure. Non-enhanced CT showed homogeneous or mildly heterogeneous low attenuation, and a punctate calcification was seen in one case. Contrast uptake was absent (n = 1) or delayed (n = 6). Progressive but incomplete enhancement was observed in three cases. On MRI, T2-weighted images showed a high signal intensity. Dynamic studies depicted the same enhancement pattern as described on CT. Ganglioneuroma is a rare tumor which should nevertheless be included in differential diagnosis of retroperitoneal masses when presenting as a well-delimited tumor with possible tendency to surround or displace major blood vessels, low density on non-enhanced CT, and delayed progressive enhancement on CT and MRI.