A patient with a Starr prosthetic heart valve for 13 years developed chronic idiopathic thrombocytopaenic purpura and a highly probable crossed allergy to heparin. As the valve needed to be replaced, cardiopulmonary bypass surgery was undertaken associating heparin with lioprost and Aprotinine. In this type of situation, aggregation of control platelets by the patient's plasma in the presence of unfractionated heparin and of low molecular weight heparin justifies the use of powerful antiplatelet agents such as lioprost which was associated with Aprotinine for its platelet protective effects. This original combination allowed successful cardiopulmonary bypass surgery under unfractionated heparin under excellent conditions with minimal blood loss. This case underlines the value of this approach for cardiopulmonary bypass surgery in patients with heparin-induced thrombocytopaenia.