Background: Patients with the hematological cancers Philadelphia-negative Myeloproliferative Neoplasms (MPNs) have an increased risk of cardiovascular disease. However, whether MPNs have an increased burden of cardiac calcification has not been thoroughly investigated. Our aim is to investigate whether patients with MPNs have an increased burden of cardiac calcification that could help explain their increased risk of cardiovascular disease. Methods and results: We recruited 161 patients (mean age 65 years, 52% men) with an MPN diagnosis between 2016 and 2018. Coronary artery calcium score (CACS) and aortic valve calcification (AVC) were measured by cardiac computer tomography, and detailed information on cardiovascular risk factors was recorded. MPNs were matched on age and sex, with 805 controls from the Copenhagen General Population Study. A CACS>400 was present in 26% of MPNs and 19% of controls (p = 0.031). AVC was present in 58% of MPNs and 34% of controls (p < 0.0001). After adjustment for cardiovascular risk factors, the odds ratio (OR) of a CACS>400 was 1.9 (95% CI 1.2–3.1, p = 0.008) in MPNs compared to controls, and the OR of AVC was 4.4 (95% CI 2.9–6.9, p < 0.0001) in MPNs compared to controls. Conclusion: Patients with MPNs have a significantly higher prevalence of a CACS >400 and AVC, compared to controls from the general population. The association between MPN and a CACS>400 or AVC remains significant after adjustment for cardiovascular risk factors. These novel data support the hypothesis that MPNs have an increased burden of cardiac calcifications, independent of other cardiovascular risk factors.