AIM: We evaluated the potential role of [18F]fluorodeoxyglucose-positron emission tomography/computed tomography ([18F]FDG-PET/CT) to identify latent infections at the site of an interim hip spacer after resection arthroplasty for hip prosthesis infection. METHODS: Twelve patients with an interim hip spacer following resection arthroplasty (Group A) were investigated. Twelve patients with painful primary hip prostheses served as controls (Group B). All underwent PET/CT before surgery. Both non-attenuation-corrected (NAC) and attenuation-corrected (AC) images were analyzed. Serum C-reactive protein (CRP) levels were measured in 22 patients. Elevated CRP level was defined as >/=10 mg/L. The diagnosis of infection was based on the results of intraoperative tissue cultures, intraoperative pathology, and clinical follow-up. RESULTS: FDG-PET/CT had 100% sensitivity and 100% negative predictive value for detection of latent infection in both groups. However, there were 4 and 3 false positive cases in Group A and Group B, respectively. Specificity improved from 50% to 62.5% in Group A, and from 62.5% to 87.5% in Group B when using NAC instead of AC. Seventeen patients had CRP values >/=10 mg/L, but only 8 were true positive for infection. FDG-PET/CT ruled out infection in 77.8% (7/9) of false-positive cases identified by CRP levels. CONCLUSION: FDG-PET/CT is highly sensitive to detect latent infections in prosthetic hips and in interim hip spacers. The high negative predictive value of PET/CT scans is useful to rule out infections in patients with persistently elevated CRP levels. PET/CT might serve as an auxiliary tool to exclude latent infections in patients posing a clinical diagnostic dilemma.