The prevalence of hypertension (HTN) in Oman is alarmingly high and patient adherence to antihypertensive medications is inadequate. This study aimed to assess the relationship between medication adherence and health beliefs among Omani patients with HTN. Methods: This descriptive cross-sectional pilot study was conducted in December 2015 and included 45 patients with HTN recruited from four primary health centres in Al Dakhiliyah and Muscat governorates, Oman. Medication adherence and health beliefs were assessed using the Morisky Medication Adherence Scale (MMAS), Beliefs about Medicines Questionnaire, Brief Illness Perception Questionnaire and the revised Medication Adherence Self-Efficacy Scale. Results: The mean MMAS score was 5.3 ± 2.0, with 48.9% of patients reporting high adherence. Higher self-efficacy and stronger beliefs regarding medication necessity were significantly related to adherence (P = 0.012 and 0.028, respectively).