Oral mucositis (OM) is among the most undesirable, painful, and expensive toxicities of cytotoxic cancer therapy, and is disheartening for patients and frustrating for caregivers. Accurate assessment of the incidence of OM has been elusive, but accumulating data suggests that reported OM frequency is significantly less than its actual occurrence. It has been suggested that over 90% of head and neck cancer (HNC) patients receiving radiotherapy (RT) with concurrent cisplatin experience severe OM with symptoms of extreme pain, mucosal ulceration and consequent limitations in swallowing and achieving adequate nutritional intake. This panoply of symptoms inevitably impacts a patients’ quality of life and their willingness to continue treatment. In spite of all the advances made in understanding the pathophysiology of OM, there is still no prophylactic therapy with proven efficacy. Strategies to limit the extent of OM and to manage its symptomatology include basic oral care, supportive medications, nutritional support and targeting aggressive treatments to high-risk patients. This review focuses on OM recognition, preventive measurements, and symptom-management strategies.