© 2019 American Society of Echocardiography Background: Lower pulmonary artery acceleration time (PAcT) is correlated with higher pulmonary artery pressure. The aim of this study was to test the hypothesis that PAcT measured in young adulthood would be associated with future cardiovascular outcomes. Methods: In the Coronary Artery Risk Development in Young Adults year 5 examination (1990–1991), PAcT was measured as the time interval from onset to peak flow velocity at the pulmonary valve annulus on Doppler echocardiography. The primary outcome was a composite of fatal or nonfatal cardiovascular disease events: myocardial infarction, non–myocardial infarction acute coronary syndrome, coronary revascularization, congestive heart failure, stroke, transient ischemic attack, carotid artery disease, and peripheral arterial disease. Results: PAcT was obtained in 4,171 participants (mean age, 30 ± 4 years, 55% women, 51% white). PAcT groups obtained using linear spline methodology were as follows: group I, PAcT ≥ 196 msec (n = 122); group II, PAcT < 196 and ≥115 msec (n = 3,195); and group III, PAcT < 115 msec (n = 854). During follow-up (median, 24.9 years), the primary outcome occurred in 216 participants (5.2%); 66 of 854 (7.7%) of those with PAcT < 115 msec, 149 of 3,195 (4.7%) of those with intermediate PAcT level, and one of 122 (0.8%) of those with PAcT ≥ 196 msec. In a fully adjusted model, the lowest and intermediate PAcT groups had hazard ratios of 8.3 (95% CI, 1.1–62.1; P =.04) and 6.8 (95% CI, 0.9–50.5; P =.06), respectively, in comparison with the highest PAcT group. Conclusions: PAcT is useful for better identifying young adults at higher risk for cardiovascular events, who may benefit from a strict control of modifiable cardiovascular risk factors.