We report a case of a 62-year-old female patient with an inflammatory reaction of the thoracic aortic wall. The diagnosis was made by computed tomographic (CT) scan, magnetic resonance imaging (MRI) and positron emission tomographic scan with 18-fluorodeoxyglucose (FDG-PET). The patient was treated with corticosteroids. The inflammatory parameters as well as FDG-uptake on PET scan returned to normal. Due to its aspecific presentation, the diagnosis of aortitis is often hard to establish. With this case the possible role of FDG-PET scan as a valuable tool in the diagnosis and monitoring of this inflammatory aortic disorder was demonstrated.