Objective: This study aimed to examine factors related to the active aging concept and functional capacity in elderly Thais. Material and Methods: The study population was 253 elderly people aged 60 years and over. The tools used for data collection were a standardized active aging concept questionnaire, which had an index of item objective congruence (IOC) of 0.938. The descriptive statistics used percentages, means, and standard deviation, and inferential statistics were calculated through stepwise multivariate linear regression to investigate the factors that impacted the functional abilities associated with active aging. Results: The results showed that functional capacity had a low to moderately positive correlated significance with mean a correlation with the willingness of the elderly people to follow or practice the active aging concept, the health service system and environmental and lifestyle factors had a moderately positive effect; and behavior had a low positive correlated significance with practice the active aging. The regression coefficients of the health service system factors and environmental and lifestyle factors had a positive relationship to the practice of active aging. Conclusion: In summary, the health service system and environmental and lifestyle factors had a positive relationship with the practice of active aging. Relevant agencies can use this as basic information for planning and promoting the development of increased functional capacity for the elderly.