This study was carried out to investigate into the amount of energy consumption for two methods of onion cropping consisting in seed planting or seedling transplantation. Plans to reduce the level of energy consumption and cost are proposed too. To determine the input and output energy, a questionnaire was designed in which the types and amounts of applied inputs at different stages of crop production were included. The results indicated that output/input energy ratio for seed planting and seedling transplanting were 0.82 and 0.95 respectively. Furthermore, for the foregoing methods, net energy gain was -62358.8 and -14333.2 MJ/ha and energy productivity was 0.24 and 0.29 kg/MJ respectively. Calculation of energy intensity revealed that for producing of one kilogram onion, it was required to consume 4.13 and 3.4 MJ energy for seed planting and seedling transplanting respectively method, respectively, indication a 21.5% energy saving when the latter method was used. Deploying modern irrigation systems, appropriated planting and harvesting machines, following recommendations from agricultural expert on fertilizers, pesticides and seeding rates would substantially reduce energy consumption and cost of onion production.