Background and aims: Myeloproliferative neoplasms (MPN) are rare hematologic diseases that require early diagnosis to prevent thrombotic events. Only a few studies have investigated transcranial Doppler (TCD) ultrasonography among these population groups. Following the PRISMA Guidelines, we reviewed the utility of TCD in Polycythemia vera (PV) and Essential Thrombocytosis (ET) patients in the context of cerebral blood flow and detection of microembolic signals (MES). Methods: This systematic review focuses on the application of TCD in MPN. By incorporating findings from one observational study, one prospective study, and three case reports, the review establishes that while TCD is not a primary tool for diagnosing PV and ET, it plays a crucial role in monitoring cerebrovascular complications, assessing thrombotic risk, evaluating treatment responses, and facilitating research related to these conditions. Results: This review incorporates findings from a total of 63 patients. 3.2% had ischemic stroke and 1.6% had transient ischemic attack with a total of 4.8% stroke risk. High-intensity transient signals (HITS) were common in 22% of patients wherein they had elevated hemoglobin, hematocrit, and platelet values. Following treatment and normalization of blood panels, 31.7% had improved cerebral perfusion with normal flow velocities. 3.2% had elevated flow velocities linked to blood flow obstruction. There was significant clinical improvement among the study population, with 17.5% becoming asymptomatic with the disappearance of MES. Conclusions: The judicious use of TCD can enhance a comprehensive diagnostic and monitoring strategy, complementing traditional clinical and laboratory assessments in the management of MPN specifically PV and ET.