Background: Hypertension is a silent killer, a time bomb in both the developed and developing nations of the world. Adherence to long-term therapy for chronic illnesses like hypertension is an important tool to enhance the effectiveness of pharmacotherapy. Aim: To assess barriers facing medication adherence among patients with chronic hypertension at outpatient medical clinics. Study design: A cross-sectional descriptive design was used. Sample: A purposive sample of 200 patients was selected. Setting: Outpatient medical clinics of Minia General Hospital in Minia City. Tools: Three tools were utilized; 1^st tool: Contains two parts; demographic data and Medical status of patients. 2^nd tool: Assessment scale of patients' adherence to antihypertensive medication. 3^rd tool: Assessment questionnaire of patients' barriers to antihypertensive medication adherence. Results: the majority of participating patients were married and about two thirds of them were illiterate. In addition more than half of them had poor adherence to antihypertensive medication, there was highly statistically significant relation between participants' level of adherence and their blood pressure measurement. Conclusion: The most frequent barriers of antihypertensive medication adherence were; fear from side effects, medication costs and unavailability or no access of medication. Recommendations: Providing medications free to patients attending health clinics to overcome cost of medication that can affect adherence to prescribed medications