The Australian Institute of Criminology was commissioned by the New South Wales Police to undertake a pilot study to monitor injuries that occurred in police custody. The purpose of the study was to determine the feasibility and utility of such a routine data collection process. This report presents the findings of the feasibility study, which involved an analysis of data gathered from the NSW Computerised operational policing system (COPS) over a 19-month period from 1 November 2001 until 30 June 2003. The study finds that a total of 260 detainees were injured during the custody process during this period, and presents an analysis of demographic and associated characteristics of those injured and characteristics of the injury incidents. The pilot study demonstrates that it is possible to monitor injuries occurring in police custody and determine the nature and extent of these injuries. The monitoring system is invaluable from a research perspective in terms of increasing knowledge and understanding of the custody process, and is also of great benefit to NSW Police as a performance monitoring system. The report also includes recommendations on ways of improving and simplifying the process.