Whether snoring increases the risk of hypertension remains unclear. The authors examined the association between snoring and risk of hypertension in a cohort of 73,231 US female nurses aged 40-65 years and without diagnosed cardiovascular disease or cancer in 1986. Blood pressure levels and physician-diagnosed hypertension were self-reported through validated questionnaires. During 8 years of follow-up, 7,622 incident cases of physician-diagnosed hypertension were reported. Older age, smoking, body mass index, waist circumference, waist-hip ratio, weight gain, less physical activity, and sleeping on the back were directly associated with regular snoring. After adjustment for age, body mass index, waist circumference, and other covariates, snoring was associated with a significantly higher prevalence of hypertension at baseline (odds ratio = 1.22, 95% confidence interval (CI): 1.16, 1.27 for occasional snoring and odds ratio = 1.43, 95% CI: 1.33, 1.5 for regular snoring). In prospective analyses using incident cases of hypertension as the outcome, the multivariate relative risks of hypertension were 1.29 (95% CI: 1.22, 1.37) for occasional snoring and 1.55 (95% CI: 1.42, 1.70) for regular snoring. In addition, snoring was associated with significantly higher systolic and diastolic blood pressure levels. These data suggest that snoring may increase risk of hypertension in women, independent of age, body mass index, waist circumference, and other lifestyle factors.