The inhibitors of platelet membrane integrin receptor glycoprotein IIb/IIIa occupy the receptor, preventing fibrinogen binding and platelet aggregation. The inhibition is direct and may be advantageous over the partial inhibition induced by agents interfering at individual pathways to platelet aggregation. The inhibitors, and more specifically abciximab, the monoclonal antibody against the receptor, are effective to prevent the acute complications associated with percutaneous intervention procedures. Based on the positive results of these trials, which have enrolled a large proportion of patients with unstable angina, and on a few pilot studies in unstable angina, large trials have been completed and are ongoing in patients with an acute coronary syndrome. It is hoped that these drugs will prevent the acute complications associated with thrombus formation, and also, past the acute phase, prevent the recurrence of the disease and rapid progression of atherosclerosis.