A method for treating ischemia by administering deltorphins to a mammal. Deltorphin I SEQ ID NO:1, delntorphin II SEQ ID NO:2 or combinations of deltorphins I SEQ ID NO:1 and II SEQ ID NO:2 may be administered. A deltorphin concentration of about 0.5-20 mg/kg body weight, or alternatively a lower concentration of about 1-1000 μg/kg body weight of the mammal in a physiologically acceptable formulation is administered up to four hours after an ischemic episode. Deltorphins may also be administered prior to or concurrently with onset of ischemia. Cerebral or spinal cord ischemia or ischemic heart disease may be treated using the method of the invention