PET/CT is an integral part of the evaluation of patients who have head and neck cancer. In this issue, the state of the art in PET/CT imaging is discussed. The issue starts with an overview of FDG-PET/CT, PET and MRI for normal anatomy, including pitfalls and artifacts. This topic is followed by a review of FDG-PET/CT for initial and subsequent therapy evaluation; progressing to PET and MRI. Other articles discuss SUV as a prognostic factor in head and neck squamous cell carcinoma, PET in head and neck cancer radiotherapy treatment planning, PET in decision making for neck dissection after radiation treatment, and newer methods for improving yield from FDG-PET imaging for accurate staging, determining tumor biology, and assessing prognosis. The issue focuses on some of the most cutting-edge applications, such as new tracers PET in head and neck squamous cell carcinoma (including FLT and hypoxia imaging). PET scans in thyroid cancer is also discussed.