The remarkably comprehensive qualitative description of the cardiovascular actions of adenosine by Drury and Szent-Gyorgyi [(1920): J Physiol 6: 213-2371 serves as a framework for current research on the cellular and molecular mechanisms of those actions. This article reviews eight areas in this field that have advanced significantly during the past 5 years:(1) the kinds of potassium channels coupled to the cardiomyocyte A1 AR;(2) the mechanism of the” anti-adrenergic” action of adenosine;(3) the role of adenosine in angina pectoris;(4) the role of adenosine in ischemic preconditioning;(5) the occurrence of AzAR in ventricular myocytes;(6) evidence for A,-, A**-, A2~-and A3ARs in blood vessels;(7) the role of nitric oxide in adenosine-initiated vasodilation; and (8) the effect of adenosine on microvascular permeability. In some areas, solid evidence has defined a particular mechanism; in others, the evidence is as yet incomplete. Drug Dev. Res. 39: 301-307, 1996