To date there have been fewer than a dozen studies on the nature of, and contributory factors in, critical incidents (CI) in anaesthesia. The first of these, by Cooper and colleagues, showed that the vast majority of their CI involved human error . Most recently, the on-going Australian Incident Monitoring Study (AIMS), with now more than 2000 reports, has shows that aspects of 'system failure' may constitute the bulk of the contributory factors, even though some human error may be detected in about 80% of the analysed cases . We set up a Critical Incident Reporting System (CIRS) to collect anonymous CI in anaesthesia using a reporting form on the Internet. CIRS analysis of the first 60 cases corroborates the findings of previous CI studies. In addition, our preliminary results have shown certain important trends, especially those concerning the contributory factor of communication in the Operating Theatre. Although to date we are unable to assess the educational importance of these CI reports, we believe that there is great potential for this aspect of CIRS.