Background: Aging population growth is accompanied by the risk of cardiovascular diseases and hypertension. Medication nonadherence is one of the problems affecting patients, especially elderly individuals with high blood pressure. Aim: The present study aimed to determine the effect of an educational program based on the Health Belief Model (HBM) on medication adherence in older adults suffering from hypertension. Methods: This randomized controlled clinical trial was conducted on 60-year-old elderly people referring to health centers in Mashhad, Iran, during 2017. To this end, the intervention group received education on medication adherence while the control group was only subjected to typical routine services. The data were analyzed in SPSS Software (Version 20) through the independent t-test, Chi-square test, and Fisher’s exact test. Results: The mean ages of the participants in the intervention and control groups were 69.1±8.3 and 63.9±6.7 years, respectively. The post-test mean score of medication adherence obtained by the intervention group was 6.7±0.5 that was significantly higher than that of the control group (3.7±1.0) (P˂0.001). Moreover, the mean score of medication adherence in the intervention group had significantly increased in the post-test phase (P˂0.001) based on the within-group results of the paired t-test. Implications for Practice: The HBM might improve medication adherence in elderly individuals with hypertension by changing their beliefs. Therefore, it was recommended to use this model for teaching self-care to older adults suffering from chronic illnesses and also in other senior healthcare centers
