ObjectiveTo estimate, with respect to age and gender, the prevalence of high blood pressure (BP) in treated and non-treated subjects and its association with other cardiovascular risk factors.DesignA cross-sectional study.SettingHealthcare centres in the centre of France.ParticipantsAll subjects (n= 61 108) who had a free health check-up, between February 1995 and September 1996.Main outcome measuresHigh BP (systolic blood pressure (SBP)>140 mmHg, diastolic blood pressure (DBP)>90 mmHg or antihypertensive therapy); diabetes (fasting glucose plasma concentration>1.26 g/l or antidiabetic therapy); hypercholesterolaemia (total cholesterol>2 g/l or lipid-lowering therapy); hypertriglyceridaemia (fasting triglycerides plasma concentration>2 g/l or triglyceridaemia-lowering therapy); overweight (body mass index⩾25 kg/m2); abdominal fat distribution (waist to hip ratio>0.9 in males and>0.8 in females).ResultsPrevalence of high BP was 37.7% in males and 22.2% in females. BP was normalized in 29.7% of treated males and 44.1% of treated females. High BP was associated with at least another cardiovascular risk factor in 83.8% of the males and 76.7% of the females with high BP. Hypercholesterolaemia was the most frequently associated risk factor. Except smoking, the prevalence of each cardiovascular risk factor was shown to increase with the severity of hypertension. Two or more other cardiovascular risk factors were present in 22.9% of the males and 9.8% of the females with high BP.ConclusionsRate of high BP, even in treated subjects, is high. More than three out of four subjects with high BP have at least one other cardiovascular risk factor.