where a non- health educated operator assesses what kind of help is needed. A specific dispatch report (DR) is used if an ambulance is dispatched. We assessed which DRs were used for the Copenhagen Mobile Emergency Care Unit (MECU) in the case of out- of- hospital cardiac arrest. Materials and method: All DRs for the MECU during 2000 to 2006 were analyzed and compared with the diagnosis recorded by the dispatched specialist in anaesthesiology after every case. We divided the DRs into five categories: ''cardiac arrest'', ''possible death'', ''unconscious'', ''heart attack'', and ''miscellaneous'' (consisting of 40 different DR categories). Results: We found 52088 DRs, 2902 of which were diagnosed as cardiac arrest. 32% of these cardiac arrests were dispatched in accordance with this, while the DRs were different from cardiac arrest in 68%. ''Unconscious'' accounted for 21%. 41% of the cases with DR cardiac arrest could not be verified upon the arrival of the dispatched medical doctor. Conclusion: Only 32% of the cases with cardiac arrest had a correct DR. We suspect that some of the patients had an unrecognized cardiac arrest at the time of contact to the alarm centre. The current alarm system can presumably be improved. The alarm centre has a central role in such a quality improvement.