Assessment of quality of life is an important measure of the impact of disease and effectiveness of treatment. The Myocardial Infarction Dimensional Assessment Scale (MIDAS) is a disease-specific questionnaire developed for the evaluation of health-related quality of life in patients following myocardial infarction. The purpose of this study was to determine the psychometric properties of the Farsi version of MIDAS. The translated MIDAS was checked for validity and reliability with 350 patients who had suffered a myocardial infarction within the last 90 days. Participants were recruited from five inpatient wards and two outpatient departments at four university hospitals in Tehran between June 2013 and March 2014. Exploratory factor analysis indicated a six-factor solution for the questionnaire: ‘physical activity’, ‘insecurity’, ‘emotional reaction’, ‘dependency’, ‘diet’, and ‘concerns over medication and side effects’. Together, these accounted for 81.63% of variance observed. Cronbach's alpha of the subscales ranged from 0.88 to 0.98, and test-retest reliability intraclass correlation coefficients ranged from .81 to .97, indicating that the instrument was reliable. The Farsi version of the MIDAS was reliable and valid for Iranian patients with myocardial infarction. The MIDAS can be used to measure health outcomes in different clinical settings and research centres, and by nurses for measuring health-related quality of life and determining the effects of medical and nursing interventions on patients' quality of life.