OBJECTIVES: Self-report questionnaires have been suggested to evaluate adherence to medications. However, their performance might vary among different communities particularly if translations are needed. We compared psychometric properties of Hill-Bone adherence scale (HBAS-14) or the medication subscale (HBAS-9) with the Morisky medication adherence scale (MMAS-8) after standard linguistic validation among Iranian hypertensive patients.  METHODS: We used standard forward-backward translation procedure to translate MMAS-8 and HBAS-14 to Persian language based on the International Society for Pharmacoeconomics and Outcomes Research (ISPOR)guideline. In a cross-sectional study, a sample of 200 hypertensive patients, who attended a referral pharmacy to fill their prescriptions, was recruited from Aug 2013 to July 2014. Clinical and demographics data was collected using a predefined form. The adherence scales were completed by face to face interview. Patients’ blood pressure was measured twice with a 5 minutes interval. the mean value was used in data analysis. To evaluate test-retest reliability, half of the study population were interviewed by telephone and the other half by a second face to face interview. We analyzed acceptability, reliability, validity (construct, convergent and criterion) using appropriate statistical tests. RESULTS: For the MMAS-8: cronbach’s α =0.41, mean inter-item correlation=0.09, mean total-item correlation=0.19, and ICC=0.49, Sensitivity=43.5%, specificity: 80.9%, LR+ =2.27, and LR- =0.70 and the construct validity analysis revealed three factors. For the HBAS-14: cronbach’s α =0.44, mean inter-item correlation=0.06, mean total-item correlation= 0.16, and ICC=0.75 and the construct validity analysis showed six factors. For HBAS-9: sensitivity=78.48%, specificity=37.17%, LR+ =1.25, and LR- =0.58. The convergent validity between MMAS-8 and HBAS-9 showed a kappa value of 0.24. CONCLUSIONS: Psychometric properties of both scales were revealed to be moderate in an optimistic viewpoint. It is recommended to use a revised HBAS-9 and a revised MMAS-8 together to achieve appropriate sensitivity and specificity. Meanwhile, a native questionnaire should be designed for Persian speaking population.