Dual energy computed tomography (DECT) is an advanced form of computed tomography (CT) in which simultaneous or near-simultaneous acquisitions are performed at two different peak energy levels, enabling material density and spectral attenuation characterization beyond what is possible with conventional CT scans. This article is a review of the current applications of DECT for the evaluation of head and neck cancer. The article will begin with a brief overview of different approaches to DECT scanning and address basic issues related to image quality and acquisition dose. This will be followed by a review of the use of different DECT reconstructions for improving head and neck squamous cell carcinoma visualization, evaluation of tumor extent, and invasion of critical structures. The article will conclude with a brief review of other emerging applications of DECT for evaluation of different head and neck cancers and advanced tumor analysis.