Aims: Persons with lower-limb amputations need to achieve more natural gait through more effort, leading to an increase in the energy consumption in them compared to the healthy persons. The aim of this study was to investigate the effects of the socket fit on gait energy consumption level in persons with lower limb amputations. Materials & Methods: In the semi-experimental study, 9 persons with below knee amputation, referred to Tehran Veterans Foundation Center, were studied in 2015. The subjects were selected via available sampling method. The study was consisted of two steps, including improper fit and proper fit conditions. The socket fitting was assessed by the trinity amputation scale and the socket comfort scale. The level of energy consumption of the subjects was measured by the physiological cost index. Data was analyzed by SPSS 19 software using paired T test. Findings: Mean values of persons’ gait speed (p=0.001) and the physiological cost index (p=0.019) with improper fit and proper fit were significantly different. Nevertheless, the difference between gait heart beat and resting heart beat at two steps was not significant (p=0.093). Conclusion: Lower energy consumption can be achieved in persons with lower-limb amputations through the utilization of a proper fit, leading to a better gait.