We investigated the hypothesis that the effects of Monitoring and Blunting coping styles are mediated in part by endogenous opioids. Mean arterial pressure (MAP) and heart rate (HR) were measured in 39 males before, during, and after a mental arithmetic stressor. Each subject experienced the protocol once under opioid blockade (naltrexone) and once in a placebo condition, in counterbalanced order. Monitoring and Blunting were assessed using the Miller Behavioral Style Scale. High Blunting and high Monitoring were both associated with poorer MAP recovery under opioid blockade than in the placebo condition. Similar effects were noted for Blunting on the measure of HR. These results indicate that the coping styles of Monitoring and Blunting may be associated with enhanced opioid mediation of cardiovascular recovery from stress.