Background: The Trans theoretical model (TTM) is developed as a framework for understanding the process of behavior changes. It is known as the most popular approach for promoting exercise behavior. The main objective of this study is to determine the relationship between regular physical activity and TTM components among members of municipality councils in selected districts of Tehran. Methods: This quasi-experimental research with non-equivalent control groups was conducted as a cross-sectional study with 207 members of municipality councils at districts 17 and 20 of Tehran. Data gathering instruments included: demographic; physical activity stage of change; processes of change (researcher-made); self-efficacy, and decisional balance questionnaires. Reliability, and construct validity were evaluated through appropriate statistical procedures. To analyze the data, applied statistical tests such as: chi-square, regression, Pearson correlation coefficient and ANOVA were performed using SPSS 22 software. Results: The level of physical activity of municipality council's members were: 43.5%, 12.1%, and 44.4% at low, moderate, and appropriate activity levels, respectively. The results showed that 18.9, 15.9, 10.1, 24.7and 30.4 percent of municipality council's members were in the pre contemplation, contemplation, preparation, operation and maintenance stages consequently. The stages of change could predict physical activity in the municipality councils (P < 0.05). However, all the components of this model were significantly associated with regular physical activity behavior. There was a significant relationship between the structures of the processes of change, benefits and barriers against regular physical activity. Conclusions: Although, 43.5% of municipality council's members did not have any intention of performing physical activities in the next six months, it is important to them to recognize the need for physical activity as the main behavior to increase physical and mental health and to be in the maintenance stage of their physical activity behavior. According to the most important predicting components in this study, educational intervention must be focused on in order to increase the effectiveness of the programs to promote municipality councils' physical activity.