Objective: A study of the prevalence of hypertension in the patient population was conducted at the University of Mississippi, School of Dentistry. Method and materials: The 3,665 records reviewed represented patients treated by undergraduate dental students from 1993 through 1997. Inclusion criteria were diagnosis of hypertension by a physician or presentation with a systolic reading of greater than 140 mm Hg or a diastolic reading of greater than 90 mm Hg. Results: Of the 1,021 subjects who met the criteria, 609 were previously diagnosed with hypertension and 412 exhibited elevated blood pressure. The prevalence of diagnosed hypertension in the study population was 16.6%. When the 412 subjects who exhibited elevated blood pressure were included, the prevalence of hypertension was 27.9%. At the initial screening, 32.2% of diagnosed adults and 27.0% of undiagnosed adults exhibited a systolic reading of 160 mm Hg or greater or a diastolic reading of 100 mm Hg or greater. For all age groups, there were no statistically significant differences in race, sex, educational level, or occupation between the diagnosed and undiagnosed groups. Conclusion: The prevalence of hypertension, often undiagnosed or uncontrolled, justifies routine blood pressure screening of dental patients.