One in 5 pregnant women is obese but the impact on later health is unknown. We aimed to determine whether maternal obesity during pregnancy associates with increased premature mortality and later life major cardiovascular events. Maternity records of women who gave birth to their first child between 1950 and 1976 (n=18 873) from the Aberdeen Maternity and Neonatal databank were linked to the National Register of Deaths, Scotland and Scottish Morbidity Record. The effect of maternal obesity at first antenatal visit on death and hospital admissions for cardiovascular events was tested using time-to-event analysis with Cox proportional hazard regression to compare outcomes of mothers in underweight, overweight, or obese body mass index (BMI) categories compared with normal BMI. Median follow-up was at 73 years. All-cause mortality was increased in women who were obese during pregnancy (BMI>30 kg/m ² ) versus normal BMI after adjustment for socioeconomic status, smoking, gestation at BMI measurement, preeclampsia, and low birth weight (hazard ratio, 1.35; 95% confidence interval, 1.02–1.77). In adjusted models, overweight and obese mothers had increased risk of hospital admission for a cardiovascular event (1.16; 1.06–1.27 and 1.26; 1.01–1.57) compared with normal BMI mothers. Adjustment for parity largely unchanged the hazard ratios (mortality: 1.43, 1.09–1.88; cardiovascular events overweight: 1.17, 1.07–1.29; and obese: 1.30, 1.04–1.62). In conclusion, maternal obesity is associated with increased risk of premature death and cardiovascular disease. Pregnancy and early postpartum could represent an opportunity for interventions to identify obesity and reduce its adverse consequences.