Background: The World Health Organization defines adherence to medication as the degree to which the person's behaviour corresponds with the agreed recommendations from a healthcare provider. The WHO describes poor adherence as the most critical cause of uncontrolled blood pressure and estimates that 50–70% of people do not take their antihypertensive medication as prescribed. Aim: To determine the level of adherence to antihypertensive medications and blood pressure control among patients attending primary health care centres. Methodology: The study was a cross-sectional and carried for three weeks on 5 PHCC in Jeddah targeting hypertensive patients over the age of 18 and excluded younger than 18 and pregnancy associated hypertension. By using a special designed questionnaire, the Hill- Bone Compliance to High Blood Pressure Therapy Scale in Arabic language. Results: This study included 432 participants; male constitutes 31.2% while females were found to be 68.8%. Age group between 55-60 years were found to be most prevalent in our study (37.6 %). More than 95% of participants were Saudi citizens. Patients with hypertension less than 1 year were 16.24%, between 1-5 years were about 30%. More than 61% of study participants were adherent to their medications while 38.46% were not adherent to medications of hypertension. Conclusion: Non-adherence to the therapeutic regimen remains a major limiting factor of hypertension management in Saudi Arabia. Overall the medication adherence was poor in hypertensive patients. Poor adherence to therapy is largely unrecognized in clinical practice. Our study suggests that, improving medication adherence in hypertensive patients can help to achieve optimal blood pressure goals and prevent further hypertension related complications. Adherence to therapeutic regimens is an important factor for optimal clinical benefits; therefore, efforts should be made by the physicians to identify the reasons for non- adherence and initiate steps to improve it. Keywords: hypertension, drug adherence, compliance.