The tightly conformal doses produced by intensity-modulated radiotherapy (IMRT), the existence of many critical structures in close proximity to the target, and the lack of internal organ motion in the head and neck, provide the potential for organ sparing and improved tumor irradiation. Many studies of treatment planning for head-and-neck cancer have demonstrated the dosimetric superiority of IMRT over conventional techniques in these respects. The initial results of clinical studies demonstrate reduced xerostomia. They suggest an improvement in tumor control, which needs to be verified in larger studies and longer follow-up.