Violence and alcohol place huge burdens on public health, affecting individuals, widersociety and public services. Many of the harms associated with violence and alcohol occur in nightlife settings and preventing these harms is a priority for the UK government. Increasingly, a public health approach to prevention is evident in both national and localpolicies and strategies. The use of data and evidence to understand the nature of the problem and to inform, target, monitor and evaluate preventive activities is fundamental to this approach. This thesis and supporting publications illustrate how my research has supported the public health approach to the prevention of violence and alcohol-related harms in nightlife and other settings. Health data, such as emergency department (ED) attendance data, has a key role to play in the public health approach to prevention. The submitted articles illustrate how I have developed the use of ED data through establishing an injury surveillance system to inform prevention policies, strategies and practice at local and national levels. My analyses have been used to: identify the extent of alcohol-related harms; inform a nightlife management strategy; target prevention activity in nightlife areas where harms were more prevalent; and monitor trends in violence and alcohol-related harms over time. Further, my work has informed national policy; the collection of enhanced ED data on the circumstances of an assault is now being promoted by the UK Government. Whilst routine data sources such as ED data can provide a vast array of intelligence onnightlife violence and alcohol-related harms they do not provide the level of detail necessary to illustrate patterns of alcohol consumption during a night out, individuals’ experience of harms that do not come to the attention of authorities, or the wide range of risk and protective factors associated with these harms. Primary research is crucial to developing this knowledge. Thus, through studies conducted in England and cross-nationally, my research has identified that nightlife settings are the scenes of excessive alcohol consumption with preloading a common feature. Subsequently, many nightlife patrons enter nightlife areas already drunk. Over-serving of alcohol to drunks is common. A range of harms are experienced by nightlife patrons including verbal and physical aggression, sexual molestation and excessive drunkenness. Both individual and environmental (i.e. venue) factors can increase the risks of nightlife patron involvement in alcohol-related harms. In the UK, the prevention of harms in nightlife settings has primarily focused on developing safe nightlife environments. Few interventions have been developed that aim to tackle the culture of drunkenness, risky drinking behaviours (e.g. preloading) and the over service of alcohol to drunks that have been evidenced in my studies. With the links between alcohol and harms, such as violence, being well established, addressing the culture of drunkenness within nightlife settings has to be a key public health priority. Both primary research and analyses of routine data sources can support this approach by identifying at-risk communities where primary prevention interventions should best be targeted.