Background/Objective: This study aims to evaluate the Functional Activities Questionnaire (FAQ; 10 items) for assessing the quality of daily living activities among older adults in Iran. Methods: A total of 680 participants completed the Persian version of FAQ. We used the Rasch partial credit model, exploratory factor analysis, confirmatory factor analysis, and receiver operating characteristic analysis to evaluate the psychometric properties of the FAQ among Iranian older adults. Results: The findings from exploratory factor analysis, confirmatory factor analysis, and item response theory analysis supported the usefulness of the Persian version of the FAQ to be used in Iran. The one-factor model of the FAQ exhibited strong internal consistency, as evidenced by McDonald’s omega (≥0.75), Factor Determinacy Index (≥0.8), and Overall Reliability of Fully-Informative prior Oblique Nonequivalent Anchor Parameter scores index (≥0.8). In addition, we observed measurement invariance and consistent response patterns for all items in a logical sequence, indicating the good internal consistency of the FAQ relevance. Conclusion: Persian version of FAQ-10 items is a valid and reliable instrument for measuring daily living activities among Iranian older adults. Significance/Implications: The FAQ will be a practical tool for measuring activities of daily living in community-based settings as part of comprehensive geriatric assessment in older adults.