BACKGROUND: Hypertension (HTN) is an important public health challenge worldwide. The prevalence of HTN varies across countries. It is necessary to obtain valid information about the prevalence of chronic condition like HTN and its predictors in different societies. Hence, this study was conducted to assess the prevalence of HTN and associated factors in Mashhad, Iran, 2015. METHODS: This cross-sectional study was performed on 2974 adults residing in Mashhad in 2015. Multistage random sampling was used. A checklist was fulfilled for each subject, and a blood sample was taken for measuring fasting blood sugar, total cholesterol, triglycerides, hemoglobin, serum creatinine, high-density lipoproteins, and low-density lipoproteins. The height and weight of participants and their blood pressure were measured according to protocols. RESULTS: The prevalence of HTN in this population was 22% (25.9% in male and 20% in female). Most interestingly, smoking and drug abuse were more prevalent in men (14.9% and 3.8%), but the sedentary behavior was more prevalent in women (51%). Interestingly, by increasing the age, the frequency of optimum, normal and high normal type was decreased and the frequency of HTN, specially sever form were increased. In binary logistic regression model, age [odds ratio (OR): 1.07, 95% confidence interval (CI): 1.06-1.09], gender (Ref:Female) (OR: 1.39, 95% CI: 1.05-1.83), and obesity (OR: 1.09, 95% CI: 1.06-1.12) were the predictors of HTN. CONCLUSION: The prevalence of HTN among this population was found to be high; which indicates the need for HTN-screening programs, especially for the elderly, male and obese population. Given the close relationship between obesity and various diseases, including HTN, practical solutions, including lifestyle interventions, need to be developed.