Objective: The aim of this study was to record blood pressure in patients during their visit to a dental clinic, with the aim of identifying those who have high blood pressure and are unaware of it, as well as those who are aware of their condition but do have their blood pressure under adequate control. Study design: We designed a cross-sectional study which included 154 patients who were seen for a dental checkup at the Primary Dental Care of the Gallician Health Service (SERGAS). All participants completed a standardized medical questionnaire after measuring their systolic blood pressure (SBP) and diastolic blood pressure (DBP), which was conducted using the protocol established by the Spanish Society of Hypertension-Spanish League for the Fight Against Hypertension (HTA). Results: In 45 patients (29%), the figures for blood pressure were recorded as SBP≥140 mmHg and/or DBP ≥90 mmHg, indicating that they may have hypertension. Only 12 of them had been previously diagnosed with hypertension, but did not have their blood pressure under adequate control. The remaining 33 had no history of hypertension and were referred to a family physician, but only 19 saw their doctor; 11 of these patients were given non-pharmacological treatment, 6 were prescribed drug treatment and no type of treatment was indicated for the other two patients. Conclusions: By screening for hypertension, especially among patients who are more than 40 years old, the dentist can play an important role in the early diagnosis.