Background: Family function is a necessary factor that influences older people’s health. The Family APGAR has been widely used to study family functions. However, there has been no Persian version of this instrument to assess family function in older people. The aim of this study was to determine the psychometric properties of the Persian version of the Family APGAR Scale to evaluate the perception of family functions. Methods: The “forward-backward” procedure was applied to translate the scale from English into Persian. The translated version was checked in terms of validity and reliability, with a sample of 281 older people selected from retirement centers. The factor structure of the scale was also tested using a confirmatory factor analysis. To test reliability, internal consistency and test–retest analyses were performed. Results: The results of the confirmatory factor analysis indicated a good structural model. Criterion-related validity was strongly supported by the pattern of association between the APGAR Scale and the social support survey. Cronbach’s α of the scale was 0.88 and test–retest reliability ranged from 0.96 to 0.98, indicating a good range of reliability. Conclusion The findings of this study suggest that the Iranian version of the Family APGAR is a valid and reliable scale to evaluate family functions in health intervention programs.