The main goal of this research is to evaluate the relationship between the built environment and public health of citizens in four different buffers of Sanandaj, Kurdistan province, Iran. There is a growing body of evidence that links the neighborhood design to public health and argues that the built environment impacts on the public health of people through the weakening or strengthening of sustainable transportation (walking, cycling, and public transportation) and physical activity. Regular physical activity has a significant impact on the health of individuals, and this can be the best way to cope with several diseases. The statistical population of this study includes people between the age of 18 and 65 years in Sanandaj city. The method used to investigate the normality of dependent variables is the Kolmogorov–Smirnov test; the assessment of the resident’s difference of physical activities is conducted through one-way variance; the impact of the built environment on physical activities is assessed through a multivariate regression test, and the effect of physical activity on the health of the individuals is evaluated through a correlation test. This study, by explaining the characteristics of the built environment in four different buffers, has exhibited that the environment supporting physical activity of pedestrians plays a critical role in increasing the amount of physical activity they engage in.