Introduction: We evaluated the predictive accuracy of the 2013 Pooled Cohorts Equations (PCE) in the Women’s Health Initiative (WHI), a multiethnic cohort of contemporary U.S. postmenopausal women.Methods: Women aged 50-79 (N=19,995) participating in the WHI with data on the risk equation variables at baseline and who met the guideline inclusion and exclusion criteria. During 10 years of follow-up, 1,247 atherosclerotic cardiovascular disease (ASCVD) events were adjudicated through medical record review by WHI investigators.Results: The WHI-adjudicated observed risks were lower than predicted. The observed (predicted) risks for baseline 10-year risk categories <5%, 5 to <7.5%, 7.5 to <10%, and ≥10% were 1.7(2.8), 4.4(6.2), 5.3(8.7), and 12.4(18.2), respectively. Small changes were noted after adjusting for time-dependent changes in statin and aspirin use. Among women 65 years and older enrolled in Medicare, WHI-adjudicated risks were also lower than predicted, but observed (predicted) risks became aligned after including additional events ascertained by linkage with the Centers for Medicare and Medicaid (CMS) for more complete capture of events: 3.8 (4.3), 7.1 (6.4), 8.3 (8.7), and 18.9 (18.7). Similar results were seen across ethnic/racial groups. Overall, the equations discriminated risk well (c-statistic 0.726, 95% CI 0.714-0.738).Conclusions: Without including surveillance for ASCVD events using CMS, observed risks in the WHI were lower than predicted by PCE as noted in several other US cohorts, but observed and predicted risks were better aligned after including CMS events.