Multiple cross-sectional epidemiologic studies have suggested an association between periodontal disease and tooth loss and hypertension, but the temporality of these associations remains unclear. The objective of our study was to evaluate the association of baseline self-reported periodontal disease and edentulism with incident hypertension. Study participants were 36,692 postmenopausal women in the Women's Health Initiative-Observational Study who were followed annually from initial periodontal assessment (1998-2003) through 2015 (mean follow-up 8.3 years) for newly diagnosed treated hypertension. Cox proportional hazards regression with adjustment for potential confounders was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Edentulism was significantly associated with incident hypertension in crude (HR (95% CI) = 1.38 (1.28-1.49)) and adjusted (HR (95% CI) = 1.21 (1.11-1.30)) models. This association was stronger among those <60 years compared to ≥60 years (P interaction 0.04) and among those with <120 mm Hg systolic blood pressure, compared to those with ≥120 mm Hg (P interaction 0.004). No association was found between periodontal disease and hypertension. These findings suggest that edentulous postmenopausal women may represent a group with higher risk of developing future hypertension. As such improved dental hygiene among those at risk for tooth loss as well as preventive measures among the edentulous such as closer blood pressure monitoring, dietary modification, physical activity, and weight loss may be warranted to reduce disease burden of hypertension. Further studies are needed to clarify these results and further elucidate a potential role of periodontal conditions on hypertension risk.