Myocardial infarction (MI) is one of the main causes of death from cardiovascular disease. Curcumin was shown to exert potent antioxidant, anti-inflammatory, antiangiogenic, antimutagenic, anticoagulant and antidiabetic activities. This study was done to investigate the protective effects of curcumin in isoproterenol (ISO) induced myocardial injury in rats. Forty-eight rats were divided into 6 equal groups. Group I: (normal control) rats received no drugs. Group II :(curcumin) rats received curcumin (200 mg/kg b.wt/day) orally for 30 days. Group III: (acute myocardial infarction) rats injected ISO (20mg/kg b.wt /intraperitoneally) twice at the 29^th and 30^th days of experiment. Group IV: (chronic myocardial infarction) rats injected ISO (20mg/kg b.wt /intraperitoneally) twice at the 1^st and 2^nd days of experiment. Group V: (acute myocardial infarction + curcumin) rats received curcumin (200 mg/kg b.wt/day) for 30 days,  then ISO was injected twice, at an interval of 24 hours, on the 29^th and 30^th days .Group VI:  (chronic myocardial infarction + curcumin) rats injected ISO at the 1^st and 2^nd days of experiment and treated with curcumin for 30 days. Blood samples and heart tissue specimens were collected at the end of experimental period (30 days) for determination of serum Creatine kinase MB (CK-MB), Lactate dehydrogenase (LDH), cardiac Troponins (cTn) and Interleukin-1β (IL-1β). Moreover, heart tissues catalase (CAT), glutathione peroxidase (GP_x), reduced glutathione (GSH) and L-Malondialdhyde (L-MDA) were also determined. The obtained results showed a significant increase in serum cardiac marker enzymes (CK-MB and LDH) activities, cTn and IL-1β concentrations in addition to L-MDA in heart tissues of ISO-induced myocardial injury in rats. However, GPx and CAT activities and GSH concentration in heart tissues of myocardial infarction induced in rats were markedly decreased. Curcumin treatment was able to protect rat myocardium against isoproternol induced myocardial ischemic damage and the protective effect was attributed to its antioxidant properties by inhibiting free radical generation.