Patients with hematologic malignancies can visit the emergency department for various reasons. We report a case of a 46-year-old male recently diagnosed with chronic myeloid leukemia (CML) who presented to the emergency department with vertigo and dyspnea. Clinical examination showed low oxygen saturation, right sensorineural hearing loss, and splenomegaly. Hyperleukocytosis in complete blood count and clinical features suggestive of poor tissue perfusion made us suspect leukostasis. Initial brain and chest imaging were normal. We treated him with leukapheresis, cytoreduction, and tumor lysis syndrome (TLS) prophylaxis. Subsequent brain imaging showed signs of reperfusion injury, which reduced after one week. The symptoms improved and the patient was discharged. Leukostasis is a medical emergency, and it is essential to consider this in patients with hematologic malignancies. Early diagnosis and treatment are crucial because the mortality rate rises to 40% if left untreated.