Background The validation of self-measurement devices has been recommended. Automatic monitor A & D UA-767 (A&D Company, Ltd, Tokyo, Japan) is well known and widely used, but not tested according to the Association for Advancement of Medical Instrumentation (AAMI) and British Hypertension Society (BHS) recommendations. Objective To perform a clinical validation for use by adults of the A&D UA-767 device according to the criteria of the AAMI and a modified BHS protocol. Methods The test concerned 101 subjects (57 men and 44 women) aged 15-85 years with arm circumferences of 22-39 cm, a systolic blood pressure (SBP) range of 89-206 mmHg, and a diastolic blood pressure (DBP) range of 53 - 122 mmHg. For each subject, three readings of the UA-767 were compared with simultaneous auscultatory measurements by two trained independent observers who used a mercury manometer and dual stethoscope. The results were graded according to the BHS (1990 and 1993) and AAMI recommendations. Results Observers showed close agreement, with mean differences of 1.1. +/- 2.4 mmHg for SEP and -0.7 +/- 2.0 mmHg for DBP. The proportion of Values agreeing to within 5, 10 and 15 mmHg were 93, 100, and 100% for SEP and 97, 100, and 100% for DBP for the two observers. The sphygmomanometer measurements were 132 +/- 24/79 +/- 14 mmHg (mean +/- SD). The average difference between the mercury sphygmomanometer and A&D UA-767 readings for SEP and DBP were, respectively, - 0.4 +/- 5.4 and -0.4 +/- 4.8 mmHg. The proportion of values agreeing to within 5,10, and 15 mmHg were 82, 94, and 98% for SEP and 80, 95, and 98% for DBP for the observers and device (A/A grade for BHS). Conclusions For an adult population, the A&D UA-767 device for the self-measurement of blood pressure satisfied the AAMI criteria, achieved a BHS grade of A/A and can therefore be recommended for monitoring blood pressure in home and clinical conditions by patients with mild-to-moderate arterial hypertension. (C) 2000 Lippincott Williams & Wilkins.