Adults born preterm have increased risk factors for cardiovascular disease. We studied the cumulative incidence of manifest coronary heart disease (CHD) and stroke in adults born preterm.We studied 19 015 people born in Helsinki, Finland, during 1924-44. Of them, 137 (0.7%) were born early (34 weeks) and 1006 (5.3%) late preterm (34 to37 weeks). We ascertained CHD and stroke from the National Hospital Discharge and Death Registers and estimated hazard ratios (HRs) by Cox regression.A total of 3027 subjects (15.9%) had CHD and 1805 (9.5%) stroke. HRs for CHD were 1.17 (95% confidence interval 0.83, 1.65) for early and 0.99 (0.85, 1.14) for late preterm. For stroke, they were 0.84 (0.50, 1.39) and 0.86 (0.71, 1.06). HRs were little changed when adjusted for childhood and adult socio-economic position and birthweight for gestation standard deviation score. They were similar for first-ever events before or after 65 years, for haemorrhagic and thrombotic stroke, and for men and women, except that the HR for CHD for women born early preterm was 1.98 (1.18, 3.30).We found no increased risk of CHD or stroke up to old age in people born preterm, although women born early preterm had a higher rate of CHD. There is a discrepancy between increased risk factors in younger generations born preterm and little or no increase in manifest disease in older age. Uncovering reasons underlying this discrepancy may give important insights into the prevention of cardiovascular disease.