Introduction: The most effective and practical strategy to maintain the health of the elderly against infectious diseases is prevention through vaccination, and despite the production of numerous vaccines around the world, the success of vaccination depends on its public acceptance. Despite the beneficial effects of vaccination in recent years, many advertisements from various groups in Iran have been against vaccination, which has targeted the elderly community in particular. The present study was designed with the aim of determining the validity and reliability of the Persian version of "Vaccination Attitude Tool (VAX)" in Iranian elderly.
Method: The present study was a methodological study and was conducted on 240 Persian-speaking elderly people who referred to health centers in Abadan city with available sampling . The data were analyzed using Cronbach's alpha, confirmatory factor analysis, content validity ratio and content validity index and using SPSS_22 and AMOS_22 software. 
Findings: The average age of the elderly was 67 years old, and 61.3% of the participants were male. The face and content validity of the questionnaire was confirmed, and the convergent validity between the VAX and Co-VASA questionnaires was reported with a Spearman correlation coefficient of -0.78. With confirmatory factor analysis, it was found that the 4 factors proposed by the instrument manufacturer are approved and the model obtained from these factors has a good fit.
The reliability of the questionnaire was also calculated and reported through Cronbach's alpha, internal consistency and inter-rater reliability of 0.89, 0.9 and 0.71, respectively.
Conclusion: The final form of the Persian version of the VAX instrument has 12 items, whose face and content validity is confirmed. The internal reliability coefficient and stability of this test are acceptable and excellent. Therefore, the Persian version of the VAX questionnaire can be used as a valid and reliable tool to determine the attitude of the elderly towards vaccination.