Acute profound thrombocytopenia may be associated with the administration of eptifibatide, a glycoprotein antagonist. A case report of a 61-year-old male is presented. The reported incidence of acute profound thrombocytopenia associated with eptifibatide is 0.1% to 1.0% and usually occurs within 24 hours following therapy. However, cases of profound thrombocytopenia have been reported to occur within 1 to 4 hours following infusion. Platelet counts should be monitored in patients receiving eptifibatide at least within 24 hours and preferably within 2 to 4 hours after administration. Submitted 5.8.06 | Revisions Received 6.28.06 | Accepted 7.17.06