AIMS: To assess the impact of therapeutic hypothermia on cognitive function and quality of life in comatose survivors of out of Hospital Cardiac arrest (OHCA). METHODS: We prospectively studied comatose survivors of OHCA consecutively admitted in a 4-year period. Therapeutic hypothermia was implemented in the last 2-year period, intervention period (n=79), and this group was compared to patients admitted the 2 previous years, control period (n=77). We assessed Cerebral Performance Category (CPC), survival, Mini Mental State Examination (MMSE) and self-rated quality of life (SF-36) 6 months after OHCA in the subgroup with VF/VT as initial rhythm. RESULTS: CPC in patients alive at hospital discharge was significantly better in the intervention period with a CPC of 1-2 in 97% vs. 71% in the control period, p=0.003, corresponding to an adjusted odds ratio of a favourable cerebral outcome of 17, p=0.01. No significant differences were found in long-term survival (57% vs. 56% alive at 30 months), MMSE, or SF-36. Therapeutic hypothermia (hazard ratio: 0.15, p=0.007) and bystander CPR (hazard ratio 0.19, p=0.002) were significantly related to survival in the intervention period. CONCLUSION: CPC at discharge from hospital was significantly improved following implementation of therapeutic hypothermia in comatose patients resuscitated from OCHA with VF/VT. However, significant improvement in survival, cognitive status or quality of life could not be detected at long-term follow-up.