Minimal data exist concerning the relationship between hypertensive pregnancy disorders and various subsequent cardiovascular events and the effect of type 2 diabetes mellitus on these. In a registry-based cohort study, we identified women delivering in Denmark from 1978 to 2007 with a first singleton (n=782 287) and 2 first consecutive singleton deliveries (n=536 419). The exposures were gestational hypertension and mild and severe preeclampsia. We adjusted for preterm delivery, small for gestational age, placental abruption, and stillbirth and, in a second model, we also adjusted for the development of type 2 diabetes mellitus. The end points were subsequent hypertension, ischemic heart disease, congestive heart failure, thromboembolic event, stroke, and type 2 diabetes mellitus. The risk of subsequent hypertension was increased 5.31-fold (range: 4.90 to 5.75) after gestational hypertension, 3.61-fold (range: 3.43 to 3.80) after mild preeclampsia, and 6.07-fold (range: 5.45 to 6.77) after severe preeclampsia. The risk of subsequent type 2 diabetes mellitus was increased 3.12-fold (range: 2.63 to 3.70) after gestational hypertension and 3.68-fold (range: 3.04 to 4.46) after severe preeclampsia. Women having 2 pregnancies both complicated by preeclampsia had a 6.00-fold (range: 5.40 to 6.67) increased risk of subsequent hypertension compared with 2.70-fold (range: 2.51 to 2.90) for women having preeclampsia in their first pregnancy only and 4.34-fold (range: 3.98 to 4.74) for women having preeclampsia in their second pregnancy only. The risk of subsequent thromboembolism was 1.03-fold (range: 0.73 to 1.45), 1.53-fold (range: 1.32 to 1.77), and 1.91-fold (range: 1.35 to 2.70) increased after gestational hypertension and mild and severe preeclampsia, respectively. Thus, hypertensive pregnancy disorders are strongly associated with subsequent type 2 diabetes mellitus and hypertension, the latter independent of subsequent type 2 diabetes mellitus. The severity, parity, and recurrence of these hypertensive pregnancy disorders increase the risk of subsequent cardiovascular events.