BACKGROUND Antiphospholipid syndrome is an autoimmune disorder characterized by a hypercoagulable state associated with circulating antiphospholipid antibodies. The presence of antiphospholipid antibodies can result in a variety of clinical symptoms, such as thrombocytopenia, stillbirth, endocardial pathologies, and recurrent pulmonary embolism. CASE REPORT We present the case of a 23-year-old man with antiphospholipid syndrome and chronic thromboembolic pulmonary hypertension who developed severe thrombocytopenia. The patient died from right heart failure before the thrombocytopenia could be managed, preventing performance of a pulmonary endarterectomy procedure. CONCLUSIONS Managing platelet counts in patients with antiphospholipid syndrome prior to major surgery is very problematic, and requires similar treatment strategy as in patients with immune thrombocytic thrombocytopenia. Platelet transfusions may further decrease platelet count, as it can trigger formation of new antibodies.