Objective: The number of out-of-hospital cardiac arrests in Iceland is about 200/year. In 2002, two prospective randomized trails showed improved outcome when mild hypothermia was induced in a very selective group of comatose patients after cardiac arrest. At Landspitali University Hospital at Hringbraut, hypothermic treatment after a cardiac arrest has been used since Mars 2002. Aim of this study was to: 1) Evaluate outcome of all comatose patients after cardiac arrest in two time periods before and after induced-hypothermia was implemented at our hospital. 2) Estimate how fast and well the patients were cooled with external cooling. Material and methods: 20 patients received hypothermic treatment after resuscitation during the period from mars until December 2002. These patients were compared with 32 other patients who did not receive hypothermic treatment after resuscitation from a cardiac arrest, during the period from January 2000 until March 2002. Information regarding, time from the arrest to beginning of resuscitation (t-1), time from the arrest to return of spontaneous circulation (t-2), time from the arrest until the cooling was actively started (t-3), time from the arrest until the lowest temperature was achieved (t-4), and how many got to the target temperature (32-34°C), where gathered from medical journals. The primary outcome measure was survival to hospital discharge with sufficientlygoodneurologicfunctiontobedischargedtohome or to a rehabilitation facility. Results: 40% of the hypothermic had a good neurologic outcome compared with 28% of the normothermic group. T-1 was 3,2 min. and 3,3 min., t-2 was 35,4 min. and 29,3 min. on average in the hypothermic group and the normothermic group, respectively. T-3 was 2,8 hours and t-4 was 9,8 hours on average in the hypothermic group. 40% of the hypothermic group did not reach target temperature. Conclusion: The results of this study show that 40% of the patients where hypothermia was induced had good neurological outcome compared with 28% of the patients where hypothermia was not induced. In contrast to other studies, the present study included all comatous patients arriving to the hospital after cardiac arrest, regardless of the type of arrythmia and the time from the arrest to return of spontaneus circulation. This study also shows that the cooling technique used is slow and insufficientinachievingthetargettemperature set in this study.