We investigated the effect of olprinone on canine myocardial pump function and myocardial damage after ischemia-reperfusion injury. Three dogs of the experimental group were given olprinone (Olprinone group) and another 3 dogs were served as control (Intact group). All animals were occluded left anterior descending artery for 60 min, followed by 6 hr of reperfusion. In the experiment, hemodynamics, infarct area, creatine kinase and troponin-I were measured. Olprinone infusion induced significantly high cardiac output value and significantly low values in left ventricular end diastolic pressure and systemic vascular resistance index after reperfusion. Also, olprinone tend to attenuate the infarct area, creatine kinase and troponin-I.