Résumé : BACKGROUND: Management of essential thrombocythemia (ET) in high-risk patients is difficult because high platelet numbers can lead to vascular occlusive events and bleeding. Therapeutic interventions in ET are limited to hydroxyurea and anagrelide; however, in Europe, anagrelide is contraindicated in patients with chronic renal disease. OBJECTIVE: The aim of this case report was to describe the use of anagrelide in a patient with ET and renal impairment. CASE SUMMARY: A 73-year-old white female patient with severe renal impairment who was diagnosed with ET was receiving treatment with hydroxyurea 1 g/d since 2001. At this time she was also receiving aspirin 80 mg/d; calcium carbonate 1 g/d; pravastatin 40 mg/d; folic acid 5 mg/d; furosemide 40 mg/d; cetirizine 10 mg/d; erythropoietin 10,000 U once monthly; a vitamin B complex, 1 tablet a day; and iron tablets 105 mg/d. In February 2007, because her white blood cell count fell to 2.1 x 10(9)/L, myelodepression was suspected and hydroxyurea was stopped. This led to enhanced platelet levels and the introduction of anagrelide at an initial dose of 0.5 mg/d that was steadily increased to 2.5 mg/d. All other treatments were continued with some dosage adjustments. Sodium bicarbonate 1 g/d and vitamin D were added to her regimen. After 18 months of anagrelide treatment, a sudden but moderate fall of platelets to 142 x 10(3)/microL with severe anemia (hemoglobin, 6.5 g/dL) was observed. The patient had anemia since 2004, but the condition worsened due to bleeding related to an ulcer at the cecal valve. The patient refused blood and platelet transfusions and surgical intervention for religious reasons. Because of hemodynamic instability, she was admitted to the intensive care unit in December 2008 and died 24 hours after admission. Conclusion: We report a case of ET and chronic renal failure treated with anagrelide and low-dose aspirin in a patient who did not receive transfusion and surgical intervention due to religious reasons, and had a fatal outcome.