We used standard, large adult, and thigh-size cuffs in random order to take BPs in 470 patients. The prevalences of definite high BP [( HBP]), greater than or equal to 160/95 mm Hg) and borderline HBP [( BHBP ], greater than or equal to 140/90 less than 160/95 mm Hg) were the same with all three cuffs in patients with an arm circumference less than 35 cm, a body mass index less than 34, and a weight of less than 95 kg. The large adult and thigh cuffs did not underestimate the prevalence of HBP in these nonobese patients. The prevalences of HBP and BHBP were twofold greater with the standard cuff than with the large adult or thigh cuffs in obese patients (arm circumference greater than or equal to 35 cm or body mass index greater than or equal to 34 or weight greater than or equal to 95 kg). Routine use of the large adult cuff will provide accurate BP measurement and avoid unneeded evaluation and treatment.