This study aimed to assess the predictors of non-adherence to antihypertensive medications in northern United Arab Emirates. In a cross-sectional, multicentre study in Ajman Emirate, 250 patients with hypertension were randomly selected from outpatient clinics. Participants answered an interview questionnaire about sociodemographic and clinical data and completed the Morisky medication adherence scale. Non-adherence to antihypertensive medication was reported by 45.6% of patients. Sociodemographic predictors of non-adherence were sex and number of children. Therapy-related predictors of adherence were hospital admissions, number and cost of medications, medication perceived effectiveness and use of traditional remedies. Patient-related predictors of non-adherence were forgetfulness, method of identifying medication and poor awareness of hypertension complications. Health-care-related predictors were regular follow up at clinics, education and counselling, frequency of changing medication by physicians and awareness of physicians' instructions.