Tooth loss is closely associated with suboptimal oral care. Suboptimal oral care can facilitate local infections. These can lead to systemic inflammation and endothelial dysfunction, which are important pathological mechanisms of hypertension. The aim of this study was to investigate the link between tooth loss and the risk of hypertension. From the national health insurance system-health screening cohort in Korea, 19,680 participants who underwent three or more health examinations, including blood pressure measurements, between January 2003 and December 2008, without any history or diagnosis of hypertension were included in this study. Hypertension was defined as the diagnosis of hypertension (International Classification of Diseases-10 code “I10–11”) accompanied by the prescription of an antihypertensive agent or at least one health examination result of blood pressure of ≥140/ 90 mmHg. Kaplan-Meier survival curves with the log-rank test were used to evaluate the relationship between oral hygiene indicators and the incidence of hypertension. Cox proportional hazard models were applied to determine the association between oral hygiene indicators and the development of hypertension. During a median follow-up of 7.4 years, 1,853 patients developed hypertension. The estimated incidence of hypertension within seven years was 8.8%. Multivariable analysis confirmed a significant relationship between the number of lost teeth and hypertension (hazard ratio: 2.26; 95% confidence interval [1.24–4.10], p = 0.007, p for trend = 0.005). There was a positive association between the number of lost teeth and the risk of hypertension in a longitudinal research. In conclusion, the number of lost teeth may be associated with the risk of development of hypertension.