Polycythemia vera (PV) is a chronic myeloproliferative neoplasm characterized by the overproduction of RBCs. In addition, the WBC and platelet counts are also increased, which differentiates PV from erythrocytosis seen with chronic hypoxia and other chronic conditions. Polycythemia vera is presumed to have a genetic basis due to mutations in the Janus kinase-2 gene. The clinical presentation may consist of symptoms related to increased blood volume and viscosity, such as headache, visual changes, and venous or arterial thrombosis; however, many cases are found incidentally with asymptomatic elevated hemoglobin levels on a CBC. Diagnosis is based on peripheral blood analysis and bone marrow biopsy findings. Management is with phlebotomy or drug therapy. The prognosis is generally good, and patient survival is anticipated to improve further with the wide use of new therapies.