It is more than 15 years since the first Medical Emergency Team (MET) system was introduced to identify patients at risk and prevent serious adverse events in Liverpool Hospital, Sydney, Australia. Since then the MET system has been introduced to many other hospitals in Australia and around the world. Standardised and complete reporting of data related to MET activity is increasingly important to identify the role and benefits of the system and to facilitate quality improvement in health care in general. A uniform method for reporting data related to MET activity will aid interpretation of results, comparisons, review and changes to the MET system. The guidelines for uniform reporting of data in relation to MET activities used in our group of hospitals are presented. Future refinement and consensus agreement on the reporting of MET data internationally should enable comparisons between MET systems in several countries.