The present study aimed to evaluate the protective effect and treatment of olive leaves administration on cardiac necrosis markers, some electrolytes, and cardiac tissue antioxidants in myocardial necrosis induced experimentally in rats by subcutaneous injection of isoproterenol (ISO). Results ISO-induced myocardial infarction in male rats resulted in a significant increase in creatine kinase, creatine kinase MB, lactate dehydrogenase, aspartate aminotransferase, glucose, potassium, and phosphorus in serum, in addition to a significant increase in glucose-6-phosphate dehydrogenase in red blood cells. In addition, it resulted in a significant decrease in serum calcium and sodium in serum. Furthermore, this study demonstrated that there was a significant decrease in heart tissue superoxide dismutase and a significant decrease in catalase activity, as well as a significant increase in heart l-malondialdehyde levels, in ISO-injected rats. Conclusion This study shows that that olive leaves administration is effective against myocardial infarction and oxidative damage in heart tissue induced by ISO in rats.