Background Gestational hyperglycemia increases the risk of diabetes in later life. However, the risk of future cardiovascular diseases (CVD) related to gestational hyperglycemia remains inconclusive. The purpose of this study was to investigate the impact of gestational hyperglycemia on the subsequent risk of CVD and its modifying factors among elderly Chinese women. Methods We conducted a case-control study of elderly women from the baseline survey of Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal (REACTION) study. Women with gestational hyperglycemia (n = 82), and controls matched by age and study site (n = 410) were included. Information on CVD, including reported coronary heart disease, stroke, or myocardial infarction, was collected through an interviewer-assisted questionnaire. Results Women with gestational hyperglycemia were more likely to develop diabetes (odds ratio [OR], 2.51; 95% confidence interval [CI], 1.50-4.18) and CVD (OR, 1.98; 95% CI, 1.05-3.74). Even without progressing to type 2 diabetes, gestational hyperglycemia was associated with an increased risk of CVD (OR, 2.88; 95% CI, 1.18-7.00). However, subgroup analysis indicated that compared with those without gestational hyperglycemia or hypertension, women with both gestational hyperglycemia and hypertension had higher risk of CVD (OR, 3.98; 95% CI, 1.65-9.58), whereas the risk estimate did not significantly change in women with gestational hyperglycemia alone (OR, 2.15; 95% CI, 0.71-6.57). Stratified analysis indicated that among those with overweight/obesity, inactive physical activity, or unhealthy dietary habits, gestational hyperglycemia increased the risk of CVD. Conclusions In elderly Chinese women, gestational hyperglycemia was associated with an increased risk of CVD in later life. This association was independent of the progression to diabetes and might be modified by lifestyle factors and hypertension.