A forty-six year-old male patient presented with complaints of syncopal attacks that last for 1-3 seconds, headache, and burning and redness on toes for the last two months. In his laboratory examination, platelet count was 1500x109/L, leukocyte count was 17x109/L, and hematocrit level was 55%. Janus Kinase 2 V617F (JAK2) homozygous mutation was detected with polymerase chain reaction (PCR). The patient was diagnosed with essential thrombocythemia (ET). In the evaluation of syncopal attacks, stenosis with a length of 2.5 cm, which constricted the right carotid artery lumen at a ratio of 65%, was detected. In this case report, the diagnosis and treatment modalities were discussed in a patient diagnosed with ET who has JAK2 mutation and carotis artery stenosis.