Objectives: To investigate repeatability, and construct and convergent validity of the Ques- tionnaire d'Activite ́ Physique pour les Personnes A ˆ ge ́ es (QAPPA), a self-reported physical activity questionnaire for the elderly. Study design: Cross-sectionalandprospective(1-yearfollow-up)datafromtwopostalsurveys among members of the medical insurance scheme of the French national education system. Methods: A questionnaire on general health and the QAPPA were sent out twice, with a 1-year interval. Participants were 60 years of age (sample size varied from 225 to 393 according to the analysis). Intraclass correlations, Bland e Altman plots (continuous variables) and kappa coefficients (categorical variable) were used for repeatability analyses. Comparison tests were performed(WilcoxonranksumtestandKruskal e Wallistest)forconstructvalidity.Chi-squared test and correlation coefficients were used to establish the convergent validity of the QAPPA. Results: The QAPPA had acceptable repeatability with a 1-year interval, with moderate test e retest correlation coefficients (from r ¼ 0.46 to r ¼ 0.64) and a fair-to-good kappa coeffi- cient ( k ¼ 0.44). It discriminated between individuals by age group (with younger persons being more physically active than older persons) and exercise behaviour (with regular exercisers being more active than non-exercisers). The QAPPA was negatively associated with decline in physical function and comorbidity, and was positively associated with self- reported health and satisfaction with body functioning. Conclusion: This study found that the QAPPA is a valid tool for assessing the physical activity of older adults. It could be used for research purposes as well as for epidemiological surveillance