Isoproterenol (ISO) is widely used to treat bronchial asthma, cardiogenic or septic shock, complete atrioventricular block, and cardiac arrest. However, it can also cause myocardial damage owing to infarct-like necrosis. Curdione, an extract of the Chinese herb Rhizoma Curcumae, has a variety of pharmacological activities, including cardioprotective effects. In this study, we investigated the protective effects of curdione and its underlying mechanisms in an ISO-induced myocardial injury model. Our results showed that curdione attenuated ISO-induced H9c2 cell proliferation inhibition and lactic dehydrogenase (LDH) release. Curdione ameliorated morphological damage and reduced the ISO-induced elevation of serum creatine kinase-MB isoenzyme (CK-MB) and LDH.Furthermore, curdione inhibited ISO-induced cell apoptosis, modulated the expression of Bcl-2 and Bax proteins, repealed the accumulation of ISO-induced reactive oxygen species (ROS), prevented mitochondrial dysfunction, and activated the Nrf2/SOD1/HO-1 signaling pathway. The above results show that curdione exerts a protective effect against ISO-induced myocardial damage by inhibiting apoptosis and oxidative stress, suggesting that curdione is a potential therapeutic strategy to prevent ISO-induced myocardial damage.