Our intensive care unit has been treating comatose patients, following an out-of-hospital cardiac arrest, with therapeutic hypothermia since 2002. In all, 139 out-of-hospital cardiac arrest patients were admitted in the 4-year period 2002-5. Of these, 27% had a favourable outcome (discharged home or to rehabilitation). Forty-one per cent of patients presenting with ventricular fibrillation (VF) and 7% of non-VF patients had a favourable outcome. No patient with an estimated time from collapse to first attempt at cardiopulmonary resuscitation over 12 min survived to hospital discharge. Twenty-two per cent of patients over 70 years were discharged home, suggesting age was not a barrier to surviving out-of-hospital cardiac arrest. The introduction of a therapeutic hypothermia clinical pathway, at the end of 2003 improved the efficiency of cooling. The percentage of patients cooled to below 34 degrees C within 4 h increased from 15 to 51% and those cooled for more than 12 h increased from 30 to 83%.