en Clinical Physiology/Pharmacology Clinical Physiology/Pharmacology Clinical research article Clinical research article <span style="font-size:12px;"><span style="font-family:Arial;"><strong>Introduction:&nbsp;</strong>It is helpful to know the rate of satisfaction with treatment for predicting treatment adherence and compliance with medical advice. Thus, measuring this parameter is important both in daily clinical care and in biomedical research. Due to the unavailability of an instrument to evaluate treatment satisfaction with medicines in Persian, this study dealt with translating and psychometrically evaluating the Persian version of the Treatment Satisfaction with Medicines Questionnaire (SATMED-Q) in chronically ill patients.<br /> <strong>Methods: </strong>This descriptive cross-sectional study was performed in two stages: translation and psychometric evaluation. After obtaining permission from the developer of the questionnaire, the process of translation was carried out based on Wild&rsquo;s model (2005). Face validity (20 chronically-ill patients), qualitative content validity (10 experts), and construct validity including confirmatory factor analysis (225 chronically ill patients), were employed to establish the validity of the questionnaire. Further, the reliability of the instrument was established by determining the internal consistency and intra-class correlation (51 chronically ill patients). The data were analyzed using SPSS23 and LISREL8.5.<br /> <strong>Results:</strong> To assess face and content validity, the questionnaire items underwent modifications based on feedback from patients and experts. According to confirmatory factor analysis, the fit index values demonstrated an appropriate alignment between the model and data. The subscales&rsquo; Cronbach&rsquo;s &alpha; coefficients ranged from 0.905 to 0.985, while the entire questionnaire&rsquo;s Cronbach&rsquo;s &alpha; coefficient was 0.875. Additionally, the test-retest reliability, as measured via the intra-class correlation coefficient, was determined to be 0.739 over two weeks.<br /> <strong>Conclusion: </strong>The Persian version of the SATMED-Q has appropriate face, content, construct, and criterion-referenced validity as well as reliability for assessing treatment satisfaction with medicines in chronically ill patients. It is also advisable to use it in clinical studies, clinical settings, education, and management.</span></span> Translation, psychometric evaluation, Treatment Satisfaction with Medicines, chronically-ill patients 38 47 http://ppj.phypha.ir/browse.php?a_code=A-10-2540-1&slc_lang=en&sid=1 Ali Khatib khatib.nurse@gmail.com 3200319475328460039101 3200319475328460039101 No Department of Nursing, Faculty of Nursing and Midwifery, Neyshabur University of Medical Sciences, Neyshabur, Iran. Maasoumeh Barkhordari-Sharifabad barkhordary_m@yahoo.com 3200319475328460039102 0000000298322280 Yes Department of Nursing, School of Medical Sciences, Yazd Branch, Islamic Azad University, Yazd, Iran. Mohammad Mahdi Pazhavand mohammadmahdi_pazhavand@yahoo.com 3200319475328460039103 3200319475328460039103 No Department of Medical Ethics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran