The relative efficacy and safety of individual thrombolytic agents. administered alone and with antiplatelet and antitthrombotic drugs, in the treatment of acute myocardial infarction are presented. The clinical benefits and risks of treatment choices are discussed in relation to the mechanisms of the formation a nd prevention of thrombus and thrombolysis. It is concluded that streptokinase, tissue plasminogen activator (t-PA), and anisoylated plasminogen-streptokinase activator complex (APSAC) significantly reduce mortality and improve left ventricular function equally, despite differences in the rate at which the achieve vascular patency, their durations of action, and the extent to which their use is associated with adverse events. The questions of how best to minimize reocclusion/reinfarction, bleeding, and stroke are discussed, with particular focus on the beneficial use of aspirin and the unresolved issue of how best to use heparin