This study investigated mobility outcome following unilateral trans-tibial or trans-femoral amputation. It was an observational study at the sub-regional amputee rehabilitation centre in Sheffield, UK. All unilateral trans-tibial or transfemoral amputees referred during the study period were included. The Harold Wood Stanmore mobility grade was recorded approximately one year following initial assessment at the centre. Of the 357 amputees referred, complete outcome data was available for 281 (78.7%). The mean age was 68 years (range 16-95), 70.1% were male, and the aetiology of the amputation was vascular or diabetic in 87.5% of cases. Trans-tibial amputations accounted for 50.5% and trans-femoral 49.5%. Almost all trans-tibial and trans-femoral amputees aged 50 and under achieved functional household and community mobility. Approximately 50% of the trans-tibial amputees aged over 50 years gained independent community mobility and around 60% household mobility. There was a significant worsening of community mobility rates with increasing age but for household mobility the differences did not reach statistical significance. Fewer than 25% of trans-femoral amputees aged over 50 achieved community mobility and around 50% achieved household mobility. There was a statistically significant deterioration in both community and household mobility levels with increasing age. This study concludes that mobility rates one year after prosthetic provision for unilateral trans-tibial and trans-femoral amputees worsen with increasing age at amputation and a higher level of amputation.