The aim of this study was to describe the epidemiology and impact of serious assault warranting in-patient care over six years and its impact on ED attendances in a large teaching hospital in Dublin over 2 years. There were 16,079 emergency assault-related inpatient hospital discharges reducing from 60.1 per 100,000 population in 2005 to 50.6 per 100,000 population in 2010. The median length of stay was 1 day (1-466) representing 49,870 bed days. The majority were young males (13,921, 86.6%; median age 26 years). Overall crime figures showed a similar reduction. However, knife crimes did not reduce over this period. Data on ED attendances confirmed the age and gender profile and also showed an increase at weekends. Alcohol misuse was recorded in 2,292/16079 (14%) of in-patient cases and 242/2484 (10%) in ED attendances. An inter-sectoral preventative approach specifically targeting knife crime is required to reduce this burden on health services.