The purpose of this paper is to investigate the interrelationships between transportation (rail and air), economic growth and carbon dioxide emissions in Iran during the period 1362-1397 using time series data and the system of simultaneous equation approach. The findings show a positive correlation between transportation (rail and air) and economic growth, as well as between transportation (rail and air) and carbon dioxide emissions. Another finding of this study is that economic growth has a significant effect on increasing carbon dioxide emissions, but increasing carbon dioxide emissions has no effect on economic growth. Based on the results, the creation and development of infrastructure related to the type of transportation in order to improve the country's economic growth is proposed.