Infected foot ulcers are common complications in diabetic patients and frequently progress to osteomyelitis. [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) has emerged as a practical and accurate imaging modality to differentiate between soft tissue infection and diabetic foot osteomyelitis (DFO). This study describes [18F]FDG PET/CT indications, diagnostic accuracy, imaging protocols, interpretation criteria and pitfalls for the work-up of DFO.