To estimate the prevalence, awareness and control of prehypertension (preHT) and hypertension (HT) as defined by JNC-7 criteria in the Trabzon Region and its associations with demographic factors (age, sex, obesity, marital status, reproductive history in women and level of education), socioeconomic factors (household income and occupation), family history of selected medical conditions (diabetes, hypertension, obesity and cardiovascular disease), lifestyle factors (smoking habits, physical activity and alcohol consumption) in the adult population. In this cross-sectional survey, a sample of households was systematically selected from the central province of Trabzon and its nine towns. A total of 4809 adult subjects (2601 women and 2208 men) were included in the study. Demographic and socioeconomic factors, family history of selected medical conditions, and lifestyle factors were obtained for all participants. Systolic blood pressure (BP) and diastolic BP levels were measured for all subjects. The persons included in the questionnaire were invited to the local medical centers for blood examination between 08:00-10:00 following 12 hours of fasting. The levels of serum glucose (FBG), total cholesterol (Total-C), high density cholesterol (HDL-C), low density cholesterol (LDL-C) and triglycerides were measured with autoanalyzer. Definition and classification of HT was performed according to guidelines from the US JNC-7 report. Prevalence, awareness, treatment and control of HT were assessed. The prevalences of HT and preHT were 44.0% (46.1% in women and 41.6% in men) and 14.5% (12.6% in women and 16.8% in men), respectively. Overall, only 41% of the hypertensive individuals had been previously diagnosed. Furthermore, 54.5% of the hypertensive subjects were being treated with antihypertensive drugs (AHD), but only 24.3% of treated subjects had their BP adequately controlled. Among all hypertensive subjects (known and newly diagnosed), only 5.43% had their BP under control. The prevalence of HT increased with age, being highest in the 60- to 69-year-old age group (84.4%) but lower again in the 70+ age group. Interestingly, the prevalence was 16.9% in the 20-to 29-year old age group. HT was associated positively with marital status, parity, cessation of cigarette smoking, and negatively with level of education, alcohol consumption, current cigarette use, and physical activity. Multinomial logistic regression analysis revealed that HT were significantly associated with age, male gender, BMI, low education level, nonsmoking, positive family history of selected medical conditions, occupation, and parity. The Trabzon Hypertension Study data indicated that HT is very common and is an important health problem in the adult population of Trabzon. Patients who are unaware of their status and treated uncontrolled hypertensives are at high risk of early cardiovascular morbidity and mortality. To control preHT and HT, effective public health education and urgent precautions are needed. The precautions include serious health education, a well-balanced diet and increasing physical activity.