Major advancements in the past decade have improved our understanding of the events that occur during acute coronary syndromes. We know that atherosclerotic plaque disruption and, ultimately, platelet adhesion, activation, and aggregation are critical in the pathogenesis of this process. We have also learned that various substrates in the biochemical pathways that lead to the final common receptor involve the glycoprotein IIb/IIIa receptor. Several trials in the 1990s focused on the development of new pharmacologic agents designed to block the activities occurring at this receptor. Abciximab (ReoPro, Centocor, Malvern, Pa) was the first agent to be used in conjunction with coronary angioplasty, but 2 additional agents were approved by the Food and Drug Administration, eptifibatide (Integrilin, COR Therapeutics, South San Francisco, Calif) and tirofiban (Aggrastat, Merck, West Point, NJ). Because no comparative trials of the 3 agents have been conducted, we are forced to compare results of trials that have taken place over a large span of time. The picture is further clouded because trial designs are not consistent, endpoints are not defined in the same manner, and catheterization techniques and standards of practice have improved since the first trial with abciximab was reported in 1994. In an attempt to make this comparison easier, I have provided a review of the major trials conducted for each agent (Table). All studies were double blind, randomized, and placebo controlled.