The objectives of this study were to evaluate the energy consumption of inputs and outputs used in the sugar beet production system and to determine the relationship between energy inputs and yield in Iran. To achieve these objectives, data were collected from 153 sugar beet farms selected using a random sampling method. The total energy input was 42,231.9 MJ ha(-1), and approximately 29% and 22% were from total chemical fertilizers and irrigation water, respectively. Approximately 57% of the total energy inputs used in sugar beet production was direct energy, while the remaining 43% was indirect. Econometric assessment indicated that energy inputs of human labor, machinery, diesel fuel, total chemical fertilizers, farmyard manure, electricity, and irrigation water made significant contributions. Human labor (0.36) and machinery (0.22) energy were found to have the highest impacts on sugar beet production. Direct, indirect, renewable, and non-renewable energy forms had positive impacts on the output level. Economic analysis indicated that the total cost of sugar beet production was $2896.5 ha(-1). Energy use efficiency was 13.4, while the benefit-to-cost ratio was 1.3. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.