Maintaining adequate nutrition in Head and Neck Cancer (HNC) patients is challenging. The rigours of radiation and the burden of the malignancy make it difficult to maintain sufficient nutrition. Poor nutrition has been linked to impaired outcome and treatment complications. HNC patients also demonstrate elevated levels of problematic alcohol use and tobacco smoking. Alcohol misuse and tobacco smoking represent key risk factors in the development of HNC, and both can undermine the efficacy of treatment. Continued use during/ post radiotherapy has been linked to cancer recurrence and reduced survival time. Tobacco smoking and hazardous alcohol consumption have also been linked to depression, poor quality of life and have the capacity to exacerbate a range of complications arising from radiotherapy. Given the prevalence, co-occurrence and consequences of poor nutrition, smoking and problematic drinking, assisting patients to improve nutrition, quit smoking and reduce alcohol use represents an important avenue for improving treatment outcomes. In the current study, we will assess a) the pattern of alcohol and tobacco use demonstrated by HNC patients undergoing radiotherapy and b) interest/ readiness to quit smoking and/ or reduce alcohol. This study is embedded within an existing stepped wedge randomised controlled trial. 400 HNC patients undergoing radiotherapy will be recruited from five Australian hospital sites. Assessments will be conducted during week one of radiotherapy, four and 12 weeks post radiotherapy. Quantity and type of alcohol will be measured using the AUDIT consumption. The FTND will be used to measure self-reported nicotine dependence. Smoking status will be verified using expired CO or salivary cotinine. Alcohol dependence will be measured at time one using the AUDIT. Recruitment is due to begin November 2012. This study will be used to inform the development of an intervention to assist HNC patients improve their nutrition, quit smoking and/or reduce alcohol consumption.