Within the United Kingdom, there is an increasingly high emphasis being placed by the government on anti-social behavior (ASB) and those methods to tackle it. In order to tackle the problem of ASB effectively, it is important that practitioners with responsibility for addressing the problem have a clear knowledge and understanding of the behaviors occurring in their locality. However, methods must first be set out for defining and measuring anti-social behavior at local levels. This report sets out a range of approaches and some of the potential strengths and weaknesses of each. In addition, it presents a series of issues for practitioners to consider when identifying the most appropriate approach. The report consists of three main sections. The first section focuses on definitions of anti-social behavior, describing definitions widely used by crime and disorder reduction practitioners and the typology of anti-social behaviors from the Home Office Research, Development and Statistics Directorate (RDS). In the second section, the report considers the benefits and purpose of collecting anti-social behavior data and examines the types of data that can be collected. The final section of the report is concerned with approaches to collecting anti-social behavior data, how different methods can be most appropriately used and the strengths and weaknesses of each approach. Sources utilized for this report were the Anti-Social Behavior Unit (ASBU) 1-day count of reported ASB 2003, ASB typology from the RDS, and a RDS follow-up study to the 1-day count based on interviews with a sample of respondents to the 1-day count including Crime and Disorder Reduction Partnerships (CDRP's), Community Safety Partnerships (CSP's) and others. In summary, data collection should enable partnerships to better plan their program of anti-social behavior work and target their resources appropriately. It should also allow partnerships to determine whether initiatives implemented to tackle anti-social behavior are effective.