Background : Anti-social behaviour affects staff physically and psychologically and has financial implications. More information on its occurrence is required for effective risk management.

Aims : We undertook to audit the complete dataset on antisocial behaviour in an urban Irish hospital. Methods Data, collected from computerised incident reports between January 2005 and December 2008, were analysed with respect to date, location, incident type, person affected, type and severity of injury.

Results : There were 3,727 incidents over 4 years, with numbers rising annually at the approximate rate of 20%. Most involved nursing staff. Incidents occurred primarily on medical and surgical wards and were usually classified as minor. Physical or verbal assaults were most frequently reported.

Conclusion : Anti-social behaviour appears to be increasing. Certain wards and categories of healthcare professionals are at particular risk. More research is required to explain factors leading to such behaviour and optimum strategies for its active management.