A brief preceding ischemia-reperfusion can reduce infarct size; this is known as ischemic preconditioning. During myocardial ischemia, massive norepinephrine is released from the cardiac sympathetic nerve terminals, reflecting the sympathetic nerve injury, and producing myocardial damage. However norepinephrine participates in myocardial protection during ischemia since its depletion in nerve terminals prevents ischemic preconditioning, and exogenous norepinephrine mimics ischemic preconditioning. Multiple-valued role of norepinephrine in myocardial ischemia, and ischemic preconditioning is discussed in review.