Retroperitoneal fibrosis is a rare fibrosing disease of the retroperitoneal tissue characterized by a significant clinico-biological polymorphism. No codified treatment exists, particularly for the primary type which is the most frequent. We retrospectively report on 7 cases of primary retroperitoneal fibrosis seen over a period of 10 years. There were 4 men and 3 women (mean age: 58 years).The most common presenting symptom was lumbar pain. A biological inflammatory syndrome and a renal insufficiency were found in 4 cases. The diagnosis was confirmed by abdominal CT scan and/or histology. Etiological investigations remained negative. The evolution was generally favourable under corticosteroids. Retroperitoneal fibrosis requires a careful etiological investigation before it is considered primary. Prognosis is good in spite of the absence of a well codified treatment.