BACKGROUND: Randomised studies suggest regional anaesthesia to have the highest morbidity and local infiltration anaesthesia to have the lowest morbidity after groin hernia repair. However, implications and results of this evidence for general practice are not known. METHODS: Prospective nation-wide data collection in a cohort of n=29,033 elective groin hernia repairs, registered in the Danish Hernia Database in three periods, namely July 1998-June 1999, July 2000-June 2001 and July 2002-June 2003. Retrospective analysis of complications in discharge abstracts, identified from re-admission within 30 days post-operatively, prolonged length of stay (>2 days post-operatively) or death. RESULTS: Complications after groin hernia repair were more frequent in patients 65+ years (4.5%), compared with younger patients (2.7%) (P