Primary retroperitoneal neoplasms (PRN) arise from diverse retroperitoneal tissues. Soft tissue sarcomas (STS) comprise the majority and are well studied. Other non-sarcomatous PRN are very rare and less familiar.To evaluate the clinicopathologic and radiologic features of non-sarcomatous PRN, as well as the outcome of complete tumor resection (TR).Retrospective data were collected on consecutive patients (June 2006 to January 2015) who underwent resection of retroperitoneal lesions at our department. Final pathology of non-sarcomatous PRN was included.The study population included 36 patients (26% with PRN). PRN were neurogenic (17%), fat-containing (3%), and cystic (6%). The preoperative diagnosis was correct in only 28%. All patients underwent TR via laparotomy (72%) or laparoscopy (28%), for mean operative time of 120 ± 46 minutes. En bloc organ resection was performed in 11%. Complete TR was achieved in 97%. Intra-operative spillage occurred in 8%. Intra-operative, 90-day postoperative complications, and mortality rates were 11%, 36%, and 0%, respectively. The mean length of stay was 6.5 ± 5.5 days. The median overall survival was 53 ± 4.9 months.Familiarity with radiologic characteristics of PRN is important for appropriate management. Counter to STS, other PRN are mostly benign and have an indolent course. Radical surgery is not required, as complete TR confers good prognosis. Expectant management is reserved for small, asymptomatic, benign neoplasms.