BACKGROUND: Early diagnosis and treatment of hypertension is imperative to prevent the complications associated with this condition. The development of accurate and convenient methods of blood pressure measurement, therefore, is indispensible. At present, the JNC V has acknowledged the use of automatic sphygmomanometer that can be used without the help of someone else. We compared automatic oscillometric sphygmomanometers manufactured by Sein Electronics, korea(SE-7000 and SE-5000) with the standard Korotkoff auscultatory mercuy sphygmomanometer meter. The correlation between these two methods were calculated to determine whether these products could actually be used in clinical practice. This study was undertaken to ensure the clinical evaluation of these two products and standardization of an antomatic sphygmomanometer in korea before it is actually used. METHODS: The study included eighty-three patients, ranging in age from 14 to 81 years, who were admitted to Hanyang University Hospital in October, 1995. The blood pressure measured by the automatic oscillometric sphygmomanometer(SE-7000) in the right arm and was compared with that measured by the standard mercury sphygmomanometer(baumanometer) in the left arm. Also the blood pressure measured by the automatic oscillometric sphygmomanometer(SE-5000) at the wrist was compared by the baumanometer in the same side arm. The correlation between these methods were determined by the paired Student`s t-test and by the simple liner regression method. RESULTS: The p value of systolic blood pressure between two methods(SE-7000 and baumanometer) in the both arms was 0.896 and correlation coefficient was 0.8286. The p value of diastolic blood pressure between this two methods was 0.352 and correleation coefficient was 0.7455. The p value of systolic blood pressure between two methods(SE-5000 and baumanomter) by the arm and the wrist was 0.00018 and correlation coefficient was 0.8588, the p value of diastolic blood pressure between this two methods was 0.000048 and correlation coefficient was 0.5944. CONCLUSION: The blood pressure measured by the SE-5000 at the wrist was statistically different from that measured with the baumanometer in the arm. Further studies are necessary to use this product in clinical practice. However, the systolic and diastolic blood pressures measured with the SE-7000 in the arm were relatively similar to those measured by the baumanometer enabling this products to be effectively used in clinical practice.