Image fusion is the process of registering and combining multiple images from single or multiple imaging modalities to improve the imaging quality and applicability. It reduces randomness and redundancy to increase the diagnostic value of images for better assessment of medical problems. Fusion imaging was designed to overcome the disadvantages of morphological and/or functional imaging, and attempts to provide inputs that improve treatment planning, resulting in better prognostication. This review attempts to summarize the techniques and their applications in head and neck imaging.