A 73-year-old man presented with acute chest pain and shortness of breath suggestive of unstable angina. A detailed investigation revealed essential thrombocythemia and coronary artery pathology. With a baseline platelet count of 2,650 × 10 3/μL, coronary artery bypass grafting became nearly impossible. Three therapeutic plateletpheresis procedures successfully lowered the platelet count to 367 × 10 3/μL. Thereafter, surgery was performed with no complications. Although a drop and rise in platelet counts were observed postoperatively, the patient could be discharged in stable condition after 14 days. Thus, therapeutic plateletpheresis reduces platelet count rapidly in essential thrombocythemia and relieves patients of acute symptoms.