IntroductionInfectious diseases cause substantial morbidity when their source and location is unknown. The impressive role of radiolabeled leukocytes in detection of infection sites is well established. MethodTen patients (5 men, 5 women, median age, 43.27 years; range, 22-68 years) underwent [F-18]FDG-WBC PET/CT for suspected infection. Result and conclusionSeven of 10 scans revealed positive uptakes with definitive sites of infection. Neither the source was localized nor the infection confirmed in the remaining three patients. [F-18]FDG-WBC PET/CT scan can serves as an important tool for diagnosis and localization of infection.