Oral mucositis is a painful and often under-reported condition, which affects the oral mucosa of individuals undergoing cancer treatment. This article examines the condition, its causes, and how to prevent, manage and treat it. It also explores the condition from the view of a family member, who watched her father undergo cancer therapy and subsequently develop oral mucositis. Looking at oral mucositis from the position of a carer will hopefully highlight the condition from a different angle. The oral cavity is an important part of the human body — sometimes described as the ‘gateway to the body’; a clean and infection-clear mouth is a basic need. The mouth enables us to eat, speak, smile, laugh and sometimes cry, so a painful mouth can impact greatly on an individual’s general health and quality of life. Therefore, understanding and managing oral mucositis can affect a patient’s cancer therapy and subsequent treatment outcomes.