The retroperitoneal tumors are seldom met in their several histological expressions. Authors totally considered 27 patients with retroperitoneal tumors and they were observed from 1975 to 1996: 21 of them were primitively cured in this Institute whereas 6 were affected with relapse or metastasis after a surgical approach which had been performed by other structures. Their operability resulted of 100% with an 87% resectability rate. The surgical mortality resulted nil while the morbidity rate was of 44%. The global survival resulted of 60% to 5 years while the disease-free interval was of 35%. The outliving to 5 years resulted of 65% with a 60% disease-free interval only in the patients who were treated in first instance. The surgical therapy represents the only treatment which can modify the clinical history of such neoplasms. Exeresis should be aggressive enough in order to obtain a total extirpation of the mass and grant a right margin of safety of sound tissue. Such radical proceeding should also be pursued in the treatment of relapses and metastases. The therapeutical efficacy is always linked to the precocity the diagnosis. A strict follow-up of the patients who underwent a surgical operation for retroperitoneal neoplasm is therefore necessary. A minority of the instances was only subjected to a complementary radio and/or chemotherapic treatment. Such protections did not significantly modify the outliving.