Cardiac arrest was induced with asphyxia to identify if naloxone alone increases resuscitation rate during cardiopulmonary resuscitation in a rat asphyxia model. The animals were randomized into either a saline group (Sal-gro, treated with normal saline 1 ml iv, n = 8), a low-dose naloxone group (treated with naloxone 0.5 mg/kg iv, n = 8), or a high-dose naloxone group (HN-gro, treated with naloxone 1 mg/kg iv, n = 8) in a blinded fashion during resuscitation. At the end of 10 minutes of asphyxia, cardiopulmonary resuscitation was started, and each drug was administered at the same time. The rate of restoration of spontaneous circulation was seen in 1 of 8, 3 of 8, and 7 of 8 animals in the Sal-gro, LN-gro, and HN-gro, respectively. The rate of restoration of spontaneous circulation in HN-gro was significantly higher than that in Sal-gro (P < .05). Naloxone (1 mg/kg) alone can increase resuscitation rate following asphyxial cardiac arrest in rats.