Introduction: Problems related to physical activities have reduced humans health. The aim of this study was to determine the benefits and barriers of physical activity in age groups of East Azerbaijan Province. Materials and Methods: This research is a descriptive - comparative study. In this study 240 participants (73 adolescents, 78 youth and 89 adults), with 52.5% female and the rest were men from three cities of East Azerbaijan province were selected by cluster random sampling. Participants completed demographic information and the «Exercise Benefits/Barriers Scale» (EBBS) with 43 items. Validity and reliability of this questionnaire was obtained in Iran. Also, in this research, validity by Cronbach' 's alpha was measured and data was analysis by SPSS/15. Findings: The highest priorities of all ages on the benefits were psychological aspects and physical performance of physical activity. With regard to barriers, environment and cost of physical activity had higher priorities. There were significant differences among three groups (adolescents, youth and adults) in benefits (P>0.005, F (10, 466)=4.815) and barriers (P>0.005, F (8, 468) =6.379) of physical activity. Also, there were significant differences among female and male in barriers (P>0.005, F (4, 235)=8.798).Conclusion: Results showed priorities of age and sex groups are different from each other. it is suggested that women should be provided suitable space for physical activity.