There is controversy as to whether the emergency department is an inappropriate site for screening for hypertensive patients. The pain and apprehension associated with many ED visits have been thought to elevate blood pressure readings falsely in this setting. To resolve this question, all patients admitted to the ED of a university hospital during a one-year period were screened prospectively for hypertension. Follow-up was attempted for patients who, on admission and discharge, had systolic pressures higher than 159 mm Hg or diastolic pressures higher than 94 mm Hg. A total of 239 patients met these criteria, and follow-up was obtained in 45% of the cases. Significant hypertension (systolic greater than 159 mm Hg or diastolic greater than 94 mm Hg) was found in 35% of these patients on follow-up. Borderline hypertension (systolic, 140 to 159 mm Hg; or diastolic, 90 to 94 mm Hg) was documented in 33% of the patients. Thirty-two percent were found to be normotensive when evaluated in a follow-up visit. The number of patients experiencing pain at the time of their initial ED visit was similar among the three groups. Almost half the patients with hypertension on follow-up needed further workup or therapy. The ED can be a useful screening site for hypertension; elevated blood pressure on discharge should ensure referral for follow-up evaluation and therapy.