Ischemic postconditioning has emerged as a clinically feasible intervention for limiting infarction in the setting of percutaneous intervention. In ischemic postconditioning, a number of cycles of a brief period of reperfusion followed by a brief period of occlusion are applied immediately upon reperfusion of the ischemic heart. Although ischemic postconditioning is protective in both animals and man, the animal studies reveal that the algorithm used in selecting the duration of the occlusion and reperfusion periods is critical to the degree of protection realized and it varies with species. The question then arises what is the best algorithm for man? The available animal and clinical data are examined in an attempt to shed light on this perplexing problem.