Objective  The aim of this study was to investigate whether the risk of developing ischaemic heart disease (IHD) later in life increases with severity and recurrence of gestational hypertensive disease. Design  Cross‐sectional population‐based study. Setting  Sweden. Population  Women (403,550) giving birth to their first child in Sweden, 1973–1982. Of this cohort, 207,054 women who also gave birth to a second child during the same period were analysed separately. Methods  All women were followed up for 15 years, starting 4–14 years after the index pregnancy. Women who suffered from hypertensive disease during pregnancy were compared with women with normal pregnancies with regard to hospitalisation for, or death from, IHD during the follow up period. Main outcome measures  Fatal or non‐fatal IHD. Results  The adjusted incidence rate ratio (IRR) for later development of IHD was 1.6 (95% CI 1.3–2.0) when the first pregnancy was complicated by gestational hypertension without proteinuria, 1.9 (95% CI 1.6–2.2) for mild pre‐eclampsia and 2.8 (95% CI 2.2–3.7) for severe pre‐eclampsia. Women with gestational hypertension in their first pregnancy but not in their second had an adjusted IRR of 1.9 (95% CI 1.5–2.4) for development of IHD. Women with hypertensive disease in both pregnancies had an IRR of 2.8 (95% CI 2.0–3.9) compared with women with two normal pregnancies. Conclusion  Severe hypertensive disease in pregnancy has a stronger association with later development of IHD than has mild hypertensive disease. Recurrent hypertensive disease is more strongly associated with IHD than is non‐recurrent disease.