Thrombolytic agents are a first-line therapeutic option for establishing coronary artery patency in acute myocardial infarction. Three fibrin-specific thrombolytics--alteplase, reteplase, and tenecteplase--are available in the United States and have undergone preliminary patency trials and large randomized, comparative, survival studies. Patency rates differ among them, although overall mortality benefit is similar. Because of this fact and the economic impact of the drugs, competition in this market is significant. Distinguishing features of the drugs will likely influence selection. Reteplase and tenecteplase offer ease of administration with bolus dosing. Increased fibrin specificity appears to play a significant role in separating them. Tenecteplase, the most highly fibrin specific, is associated with decreased risk of noncerebral bleeding and reduced need for blood transfusions in all patients, as well as longer survival in those with late presentation acute myocardial infarction. Current trials will reveal the role of these agents in combination with glycoprotein lIb-IIIa receptor antagonists.