Fluorodeoxyglucose PET/CT is a powerful tool for staging head and neck squamous cell carcinomas and nasopharyngeal carcinomas. These tumors consistently display high fluorodeoxyglucose uptake, and the PET results are also valuable in terms of prognosis, whether they are obtained before treatment or after its completion. Tumors of the head and neck present distinct clinical features. Evaluating differences in biology among tumor, inflammation, and normal tissue with high physiologic uptake by performing dual time point imaging or post hoc analysis of tissue heterogeneity may also prove highly valuable, although clear clinical data are lacking at this stage.