The purpose of this study was to determine the prevalence of arterial hypertension (HT) awareness and the influence of age, sex and body mass index on the degree of control of HT in the population of Maracaibo, State of Zulia, Venezuela. It included 7424 subjects, 3640 males (M) and 3784 females (F). Information was collected through domiciliary visits with a questionnaire designed for this purpose. Hypertension was defined as such when values were > or =140 mm Hg for systolic blood pressure (SBP) and > or =90 mm Hg for diastolic blood pressure (DBP). In the total sample, 36.9% were hypertensive. A higher prevalence in M (45.2%) than in F (28.9%), was observed. The percentage of HT increased with age in both genders. There was a high percentage of hypertensives with obesity (73.5%) which did not vary when discriminating for gender and age. Obese subjects were more prone to have HT until age 50. Those younger than 40 took less medication but were proportionally better controlled. Of the hypertensive population 54.3% were not aware of their condition, of 45.7% remaining, 22.8% did not have regular control visits, 18.4% inspite of medication were not controlled and only 4.5% were well controlled. Better control was observed in F (6.2%) than in M (3.3%), P < 0.001. It is concluded that HT is a serious public health problem because of its high prevalence and lack of control, and it is necessary to implement educational and medical programmes for the detection and control of this disease.