Chronic periaortitis is an inflammatory and fibrosing disease presenting as periaortal fibrosis and formation of aortic aneurysms which are mostly localized in the retroperitoneum and occasionally in the mediastinum. Inflammatory vasculitic involvement of large vessels is also possible. In addition to symptoms of systemic inflammation, mechanical complications also occur whereby obstruction of the ureter is the most frequent. The diagnosis is made by contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) and if the findings are atypical the diagnosis should be confirmed by biopsy. After exclusion of a secondary genesis, in which case therapy of the underlying illness would be necessary, idiopathic chronic periaortitis can be treated with steroids. In cases of refractory and relapsing courses the administration of further immunosuppressive medication can be necessary. Duration of therapy, dosage and indications for immunosuppressive medication are currently unclear and have to be defined in further randomized controlled trials with larger cohorts. If complications occur, interventional or operative treatment can be necessary; in cases of hydronephrosis the placement of double-J-stents is usually sufficient.