Abstract: This invention relates to a method of prevention and/or treatment of thrombosis in a mammal without significantly altering bleeding time or coagulation. This invention further relates to methods of using selective inhibitors of the binding of vitronectin to the .alpha..sub.v .beta..sub.3 receptor, alone or in combination with other therapeutic agents, for the inhibition of thrombus formation and/or the treatment of thromboembolic disorders.