The pharmacological effects of propolis have mainly been investigated in various fields of medicine as an essential resource for the prevention and treatment of diseases. This study examined the cardioprotective effect of hydroalcoholic extract of Brazilian red propolis (BRPHE) against isoproterenol (ISO)-induced myocardial infarction in rats. Rats were pretreated with BRPHE (50, 75, and 150 mg/kg) for 30 days, with concurrent administration of ISO (85 mg/kg) during the last two days. The hemodynamic, biochemical, histological, and morphometric changes were monitored from control and experimental groups at the end of the experiment, i.e., on the 31st day. Phytochemical compounds were determinated by the UV–Vis spectrophotometric and UPLC-DAD-UV–Vis methods. ISO-induced myocardial infarcted rats showed an increase in cardiac marker enzymes, i.e., in creatine kinase-NAC (CK-NAC) and CK-MB, tachycardia, myocardium necrosis, edema, hemorrhagic areas, infiltration of inflammatory cells like lymphocytes, and increased myocardial infarct size. However, pretreatment of ischemic rats with BRPHE significantly inhibited these effects of ISO. Thus, histopathological findings obtained for the myocardium further confirmed the biochemical findings. Flavonoids and phenols were identified in BRPHE. Our results suggested that BRPHE pretreatment ameliorated myocardial injury in ISO-induced myocardial infarcted rats and exhibited cardioprotective activity. Display omitted