Résumé : Aim: The aim of this study was to evaluate retrospectively the usefulness of [18F]fluorodeoxyglucose (FDG)-PET/computed tomography (CT) in patients affected by human immunodeficiency virus and suffering from fever of unknown origin (HIV-associated FUO). Material and methods: Ten patients (six males, four females, age 24-48 years) suffering from HIV-associated FUO were studied by FDG-PET/CT. Final diagnosis was established either by microbiological or histopathological analysis or by a more than 6-month follow-up. FDG-PET/CT was regarded as 'helpful for diagnosis' when the abnormal uptake pointed to the organ or location where the cause of fever was thereafter identified. Results: Nine out of 10 FDG-PET/CT were abnormal and the cause of fever was further demonstrated by other diagnostic procedures. An infectious process (tuberculosis) was diagnosed in six patients and a neoplasm in three (two lymphomas, one Kaposi's sarcoma). FDG-PET/CT directly suggested sites for biopsy in six patients (tuberculous lymphadenitis and neoplasm). The only patient with normal FDG-PET/CT suffered from drug-induced fever. Conclusion: FDG-PET/CT is a valuable tool in patients with HIV-associated FUO. FDG-PET/CT was categorized as 'helpful for diagnosis' in nine out of the 10 patients we studied. Adding the CT anatomical landmarks to the PET findings allowed an accurate and easy localization of the sites to be punctured in the six patients in whom histopathological diagnosis was needed. © 2009 Wolters Kluwer Health