OBJECTIVE: To examine the effect of maternal gestational weight gain (GWG) on adult offspring mortality, cardiovascular morbidity and cerebrovascular morbidity. METHODS: The Aberdeen Children of the Nineteen Fifties (ACONF) is a population-based cohort of adults born in Aberdeen, Scotland between 1950 and 1956. GWG of the mothers of cohort members was extracted from original birth records and linked to the data on offspring morbidity and mortality up to 2011 obtained from Scottish national records. HRs for cardiovascular events and mortality in offspring according to maternal weight gain in pregnancy were estimated adjusting for maternal and offspring confounders using a restricted cubic spline model. RESULTS: After exclusions, 3781 members of the original ACONF cohort were analysed. Of these, 103 (2.7%) had died, 169 (4.5%) had suffered at least one cardiovascular event and 73 (1.9%) had had a hospital admission for cerebrovascular disease. Maternal weight gain of 1 kg/week or more was associated with increased risk of cerebrovascular event in the offspring (adjusted HR 2.70 (95% CI 1.19 to 6.12)). There was no association seen between GWG and offspring’s all-cause mortality or cardiovascular event. Adult offspring characteristics (smoking, body mass index (BMI) and diabetes) were strongly associated with each outcome. CONCLUSIONS: Maternal GWG above 0.9 kg/week may increase the risk of cerebrovascular disease in the adult offspring, but not all-cause mortality or cardiovascular disease. Health and lifestyle factors such as smoking, BMI and diabetes in the adult offspring had a stronger influence than maternal and birth characteristics on their mortality and morbidity.