BACKGROUND: We estimated the effect of obesity on the incidence of cardiovascular disease (CVD) and mortality in women according to menopausal status. METHODS: Women aged 40 to 69 years under routine health check-ups provided by the National Health Insurance Service in 2009 were followed up till 2018 (n=2,208,559). RESULTS: In premenopausal women, a significant increment of mortality rate was found in underweight and obesity class II (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.31 to 1.67; and HR, 1.25; 95% CI, 1.12 to 1.39) compared to normal body mass index (BMI); overweight and obesity class I did not affect mortality rate. In postmenopausal women, obesity as well as overweight status reduced the risk of mortality compared to normal BMI (HR, 0.86; 95% CI, 0.83 to 0.88; and HR, 0.84; 95% CI, 0.82 to 0.86). By contrast, there was a linear association between CVD and BMI above the normal range irrespective of menopausal status, which was attenuated in diabetic women. CONCLUSION: The current study replicated the J-shaped relationship between BMI and mortality, being more prominent in the postmenopausal group. The risk of CVD was linearly increased as BMI was increased above the normal range irrespective of menopausal status.