&NA;Cardiac mitochondria showed significant uncoupling of oxidative phosphorylation after rats were given intraperitoneal alcohol. The rate of oxygen utilization in the absence of ADP was increased while there was no significant change in oxygen utilization in the presence of ADP. These in vivo results were confirmed with in vitro experiments. Also, intraperitoneal alcohol increased the mortality of blunt cardiac trauma. The alterations in cardiac energy metabolism demonstrated may explain the increased mortality in alcohol‐pretreated animals subjected to cardiac contusion.