Systemic Arterial Hypertension (SAH) is a disease with high prevalence and low control rates. The number of undiagnosed hypertension patients is considered itself as an important public health problem. Objectives: To evaluate the epidemiology of hypertension in the city of Cajazeiras, PB. Material and Methods: This was an analytical, descriptive and cross-sectional study carried out in the city of Cajazeiras, PB. We randomly selected some districts of Cajazeiras. Their blocks were divided into strata and residents of each stratum were visited three consecutive times within a two-month interval. We measured subjects’ SAH, waist circumference, height and weight, and we applied a questionnaire relating to cardiovascular RF to all participants. The chi-square and Fisher exact tests were used to compare proportions. It was considered a significance level of 5% (p less than 0.05). Results: This study included a total of 656 participants, of which 68.43% were female. The overall prevalence of hypertension was 33.84%, including 8.38% of undiagnosed cases. With regard to the hypertensive population, 63.06% were female. Of the total of hypertensive subjects, 27.02% had not been previously diagnosed. The main RF found were: sedentarism (69.6%), history of hypertension (58.4%), excessive consumption of salt (53.7%), overweight or obesity (52.5%). Conclusion: It was identified a high prevalence of subjects with undiagnosed hypertension in this population (8.38%), mainly corresponding to male young adults. The low rate of SAH control and high prevalence of modifiable risk factors in this population should also be highlighted. DESCRIPTORS Risk Factors. Health Profile.Hypertension.