Background: In recent years, therapeutic hypothermia (TH) has been used to improve outcomes in patients with out-of-hospital cardiac arrest (OHCA). Despite these recommendations, many centers are still hesitant to implement such hypothermia protocols. In this study, we assessed the effects of TH for OHCA patients. Methods: A total of 58 OHCA patients who had return of spontaneous circulation after OHCA presumed to be due to cardiac causes were enrolled. Twenty-three patients underwent TH, which was performed using a large volume of ice crystalloid fluid infusions in the emergency room and conventional cooling blankets in the ICU to maintain a body temperature of 32-34 C for 24 hours using a tympanic thermometer. Patients in the control group received standard supportive care without TH. Hospital survival and neurologic outcomes were compared. Results: There were no significant differences between the groups in patient characteristics, underlying etiologies and disease severity. In the 23 patients who received TH, 17were alive at hospital discharge. In the 35 patients who received supportive care, only 11 were alive at hospital discharge (73.91% vs. 31.43%, p = 0.0015). Approximately 52% of the patients in the TH group had good neurologic outcomes (12 of 23) compared with the 20% (7 of 35) of the patients in the supportive group (p = 0.01). Conclusions: TH can improve the outcomes of OHCA patients. Further large-scale studies are needed to verify our results.