The objective of this study was to investigate how rapidly the Emergency Medical System provides life support to patients suffering out-of-hospital cardiac arrest in Milan, Italy. The study population included 1426 consecutive participants with out-of-hospital cardiac arrest between January 2007 and October 2008. The mean age was 72.7 years. The incidence of ventricular tachycardia/ventricular fibrillation as the presenting rhythm was 12.7%. Eighty percent of out-of-hospital cardiac arrests occurred at home and bystander cardiopulmonary resuscitation (CPR) was in progress in 11.1% of all cases. The mean time interval from collapse-to-first shock was 18.67+/-5.37 min. The mean Emergency Medical System unit response time interval was 7.07+/-3.14 min; time elapsed from arrival-to-first CPR was 7.75+/-4.32 min. In conclusions, the dispatch to arrival and dispatch to CPR intervals are comparable with those reported in other large urban areas, but the time from arrival-to-first CPR was longer than recommended by current guidelines.