Background: Hypertension is a prevalent health problem with serious complications. Adherence to antihypertensive medications (AHMs) is a key in control of hypertension and prevention of complications.  Objectives: This study aimed to estimate the rate of adherence to AHMs, and to predict factors that are likely affect adherence to these medications. Methods: A cross-sectional study was conducted from July to December 2018 including 473 hypertensive patients attending the outpatient clinics of two primary health care centers in Gharbia and Menoufia governorates, Egypt.  The Hill-Bone questionnaire was used to assess adherence level. Factors related to adherence were evaluated through questionnaire items. Results: The rate of good adherence was only 40.2%. Significant predictors of good adherence were older age (p < 0.001; OR=0.335, 95% CI= (1.232-1.585), higher level of education (p < 0.001; OR=2.538, 95% CI= (3.476-46.082), duration of hypertension > 10 years (p < 0.001; OR=0.34,  95% CI= (0.184-0.628), using one medication (p < 0.002; OR=1.553, 95% CI= (1.783-12.522), and once per day dosing (p < 0.001; OR=3.364, 95% CI= (11.637-71.781). Self-payers (p < 0.001; OR=-3.141, 95% CI= (0.02-0.096), and patients reporting poor physician relationship (p < 0.001; OR=-1.731, 95% CI= (0.540-0.578) were predictors of poor adherence.  Conclusion: A low rate of adherence to AHMs was recognized. The study highlights the importance to simplify the dosing and frequency of medications, to improve the patient-physician relationship, and the need for policies to extend the umbrella of health insurance in Egypt to overcome the economic barrier of adherence.