Purpose:To compare blood pressure (BP), hypertension (HT) history, oral diseases, and potentially associated factors among dental patients in Thailand and explore the associations among them. Methods: This study included 709 patients. Demographic data, BP levels, oral diseases, xerostomia, anxiety, depression, and associated factors were evaluated. Results: One-third of the patients were male; patients with a history of HT were older than those without (P < 0.001). In total, 53 (7.5%) had such a history, and HT was controlled in 29 (54.7%) of them. Patients with possible HT (BP ≥140/90 mmHg; 94 in total, 13.3%) were five times more likely to have a definitive diagnosis of HT than those without possible HT (odd ratio [OR] = 4.95; 95% confidence interval [CI]: 2.76-8.87; P < 0.001). They also had an increased tendency to be taking antidyslipidemic (OR = 5.54; 95% CI: 2.90-10.60; P = 0.001) or antidiabetic (OR = 4.80; 95% CI: 1.91-12.08; P = 0.001) drugs. Male sex (ß = 0.156, P < 0.001), higher age (ß = 0.299, P < 0.001), higher body mass index (ß = 0.410, P < 0.001), and periapical tissue diseases (ß = 0.073, P = 0.019) were significantly associated with elevated systolic BP. Severe periodontitis (ß = 0.081, P = 0.023) and a comparable association pattern with systolic BP were related to diastolic BP. Multivariate analysis revealed no significant association between BP and tooth loss, xerostomia, smoking, education level, anxiety, or depression. Conclusion: Dentists play an essential role in screening for undiagnosed and uncontrolled HT. Significant associations were noted between oral inflammatory diseases and high BP.