This report from the Egyptian National Hypertension Project presents national estimates of the prevalence of hypertension and the extent to which high blood pressure is being detected, treated with medications, and controlled in the Egyptian population. The results are based on findings from a national probability survey of adults > or = 25 years of age conducted in six Egyptian governorates. With the use of a stratified multistage probability design, 6733 people (85% response rate) were examined. Hypertension was defined as systolic pressure > or = 140 mm Hg, and/or diastolic pressure > or = 90 mm Hg, and/or reported treatment with one or more antihypertensive medications. Overall, the estimated prevalence of hypertension in Egypt was 26.3%. Hypertension prevalence increased progressively with age, from 7.8% in 25- to 34-year-olds to 56.6% in those 75 years or older. Hypertension was slightly more common in women than in men (26.9% versus 25.7%, respectively). Overall, 37.5% of hypertensive individuals were aware that they had high blood pressure, 23.9% were being treated with antihypertensive medications, and 8.0% were under control (systolic pressure < 140 mm Hg and diastolic pressure < 90 mm Hg). Hypertension prevalence as well as awareness, treatment, and control rates varied by region, with Cairo having the highest prevalence (31.0%) and the Coastal Region having the highest control rate (15.9%). Rates of awareness, treatment, and control tended to be lowest in areas of lower socioeconomic status. Our results indicate that hypertension is highly prevalent in Egypt and that the rates of hypertension is awareness, treatment, and control are relatively low.(ABSTRACT TRUNCATED AT 250 WORDS)