Purpose: Aim of this study is to investigate determining the mobility grade and energy consumption in congenital and acquired child amputees. Material and methods: A total of 41 children whose ages varied between 8-17 years participated in the study. Prosthetic fitting, prosthetic training and rehabilitation were given to the children. The assessments were performed in their first attendance, after three weeks of prosthetic training and 6 months after their discharge. Amputee Mobility Predictor Scoring Form (AMPQ) was applied with and without prostheses. Energy consumption was evaluated by six minute walk test. Results: It was seen that there was no significant difference in the physical characteristics of the two groups (p>0.05). The evaluation of data between the groups showed significant difference In favor of the congenital group with respect to AMPQ in the first and in the second assessment done three weeks after (p<0.05). There was no significant difference between the two groups when the same evaluations were performed six months after their discharge (p>0.05). While evaluation with the physiological cost index energy consumption was found better in the congenital child amputees at the end of the three weeks training (p<0.05), no significant was found difference between the groups 6 months after their discharge (p<0.05). Conclusion: To conclude, it can be said that the age, amputation level and cause are very important criteria in development of the mobility grade in the early period, functional fitting of child and the period of prosthetic use are significant when later outcomes are considered. Also with prosthesis specially designed for the child mobility grade increases while energy is used more economically.