Myeloproliferative neoplasms (MPNs), with an expected increment in number, impose substantial economic and social burdens. To this end, we conducted a nationwide population-based descriptive epidemiology study. We also investigated medical cost associated with MPNs. Prevalence was the highest for essential thrombocythemia (ET) (range 4.1-9.0 per 100,000), followed by polycythemia vera (PV) (range 2.8-5.4 per 100,000) and primary myelofibrosis (PMF) (range 0.5-0.9 per 100,000). ET incurred the highest cumulative total cost at US$35 million and the most frequent hospital visits, while PMF incurred the highest average cost per person at US$5000. The mean hemoglobin level was 16.9 +/- 2.2 g/dL for PV males and 15.5 +/- 2.7 g/dL for PV females. Further analyses on hemoglobin levels showed the true positive rate of PV from the significantly elevated hemoglobin group (defined as >18.5 g/dL for men and >16.5 g/dL for women) was 3.01% and that of MPNs was 3.1%. Here, we provide the biggest population-based report on MPN epidemiology that can readily be used as a representative Asian data.