Positron emission tomography-computed tomography (PET/CT) is commonly used in the staging and restaging of head and neck squamous cell carcinoma (HNSCC). In this review paper we discuss the scenarios in which PET/CT that can affect the management of HNSCC patients. These include locating a carcinoma of unknown primary, staging the clinically node-negative neck, pretreatment staging of advanced disease, and post-treatment evaluation. We summarize the evidence for these uses on the basis of recent literature and also discuss emerging applications of PET/CT for HNSCC. These are topics that radiologists commonly encounter in clinical practice and on head and neck tumor boards.