Background: The factor structure of the Short Form Health Survey (SF-36) and its application to older people in Eastern countries has been the focus of limited research. Four theoretical and experimental factor structures of the SF-36 were tested and compared here to establish a best-fitting model for Iranian older people. Methods: A sample of 391 participants (60-89 years) years completed the Farsi SF-36. A confirmatory factor analysis assessed the fit and viability of the measurement model. Three theoretical and experimental factor structures of the SF-36 were tested using an exploratory principal component analysis to explore the factor solution of the Farsi SF-36. Results: An exploratory factor analysis identified the two factor solutions (mental and physical) to be the same as the original US model, but the fit indices of the confirmatory factor analysis identified the two and three factor model (mental, physical and well-being) to be the same, making the latter more extensive for use with older people. Conclusion: This study provides strong evidence that the Farsi SF-36 has the potential to measure well-being status of older people. Such an application is valid if the Vitality items are modified and new items are developed for the Well-being scale.