Oral diseases and masticatory dysfunction are more prevalent in hypertensive patients and may hinder blood pressure (BP) control during pharmacological treatment. However, the effect of the oral function on cardiovascular outcomes in patients with poorly controlled hypertension remains unclear. A total of 5 484 middle-aged and older hypertensive patients receiving antihypertensive medications without prior cardiovascular diseases (CVD) (mean age: 67.5 ± 8.0 years) were followed to investigate incident CVD. Cox proportional hazards models were used to examine associations between the baseline oral status (number of remaining teeth and denture use) and the risk of developing CVD, stratified by BP control status. Poorly controlled BP was defined as systolic BP (SBP) ≥ 130 mmHg or diastolic BP ≥ 80 mmHg. Over a mean follow-up period of 9.9 ± 2.7 years, 567 individuals (10.3%) experienced CVD events. In the poorly controlled BP group, tooth loss and non-use of dentures were significantly associated with an increased risk of CVD; the hazard ratios (95% confidence intervals) were 1.79 (1.28-2.48) for 10-19 teeth, 1.37 (0.97-1.94) for 1-9 teeth with denture use, 1.56 (1.13-2.17) for no teeth with denture use, and 2.17 (1.30-3.64) for 0-9 teeth with non-use of dentures, compared with ≥20 teeth. This association differed significantly between the poorly controlled and well-controlled BP groups (P for interaction = 0.016). In conclusion, tooth loss and non-use of dentures are associated with a higher risk of CVD among adults with poorly controlled hypertension, suggesting that BP control status under treatment modifies this association.