Patients with myeloproliferative neoplasms (MPNs) are at increased risk of cardiovascular disease (CVD), including acute coronary syndrome (ACS). However, data on long-term outcomes of patients with MPN who have had ACS and risk factors for all-cause death or CV events post-ACS hospitalization are lacking. We conducted a single-center study of 41 consecutive patients with MPN with ACS hospitalization after MPN diagnosis. After a median follow-up of 80 months after ACS hospitalization, 31 (76%) experienced death or a CV event (myocardial infarction, ischemic stroke, or heart failure hospitalization). After multivariable Cox proportional hazards regression, index ACS within 12 months of MPN diagnosis (HR 3.84, 95% CI 1.44–10.19), WBC ≥ 20 K/µL (HR 9.10, 95% CI 2.71–30.52),JAK2mutation (HR 3.71, 95% CI 1.22–11.22), and prior CVD (HR 2.60, 95% CI 1.12–6.08) were associated with increased death or CV events. Further studies are warranted to improve cardiovascular outcomes in this patient population.