Background To assess the response time and the details of the operating procedure of the Beijing 120 Emergency Medical Service (EMS).

Methods Between June and December 2005, 51 918 EMS cases recorded in the Dispatch Center of the Beijing Emergency Medical Center were analysed.

Results The median response time of the 51 918 cases was 16.5 min; the cumulative proportions were 2.28%, 9.64% and 18.04% for less than 5 min, 8 min and 10 min of response time respectively, whereas the proportion was 19.20% for more than 30 min of response time.

Conclusions On the basis of this analysis, the response time of the Beijing 120 EMS system was found to be longer than that indicated by the national standards.