Definitive chemoradiotherapy is the basic treatment for locally advanced squamous cell carcinoma of the oropharynx. Switching from 3D conformal radiotherapy to intensity modulated radiotherapy (IMRT) significantly reduced toxicity, dry mouth and long-term swallowing problems. These changes are confirmed by groundbreaking studies on head and neck cancer. Toxicity issues are increasingly important due to shifts in disease epidemiology. Oropharyngeal cancer is now more common in younger patients with an expected longer survival. These patients are often associated with human papillomavirus infection.