This study was carried out to evaluate the energy flow, GHG emissions, and global warming potential (GWP) in corn production in western Iran. The Data was collected by split plot Design based on randomized complete block design with four replications. The treatments consisted of a combination of three levels of the main tillage factor including conventional tillage (CT), minimum tillage (MT), no-tillage (NT), and three levels of chemical fertilizer including no fertilizer or N0P0K0 (NPK) 0 , N50P50K50 (NPK) 50 and N100P100K100 (NPK) 100 . The results of this study showed that the total input energy in CT systems, MT, and NT was 56113.24, 51403.70, and 49144.45 MJ ha −1 , respectively. The output energy in this tillage systems was 111989.11, 113312.80 and 109516.68 MJ ha −1 respectively. By reducing the rate of fertilizer, the amount of input and output energy was decreased. The NT and MT systems had higher energy efficiency than the CT one. Energy efficiency in (NPK) 0 , (NPK) 50 and (NPK) 100 was calculated to be 2.62, 2.53, and 1.88, respectively. The highest amounts of CO 2 , N 2 O, and CH 4 were observed in corn production with CT systems. In no-fertilization treatments, GHG emissions were also lower. Moreover, the results showed that by decreasing tillage and increasing amount of fertilizer, GWP decreased. According to the results of this study, changing the practice of tillage from CT to MT and reducing fertilizer amount could increase energy efficiency in the region and reduce GHG emissions.