The authors, o the basis of a retrospective analysis of a series of 13 cases of chronic periaortitis, after a review of the literature about the subject, discuss about the most recent theories about pathogenesis, pathological anatomy, diagnosis and treatment of this condition. At first the authors stress the importance of adopting the term chronic periaortitis to describe any idiopathic fibrotic retroperitoneal process, as a consequence of the well established relationship between the atherosclerotic abdominal aorta an the development of this condition. Histological, immunohistochemical and immunological studies, consented to clarify the pathogenesis o the lesion. CT or MRI currently makes the diagnosis but histological confirmation is desiderable. Surgical therapy plays still a fundamental role in the management of chronic periaortitis, but the use of immunosuppressive drugs is to be considered extremely promising.