OBJECTIVE To investigate the differences in energy consumption by patients with hip disarticulation between prosthetic walking and wheelchair locomotion. METHODS : The subjects consisted of seven amputees, all older than 60, with unilateral hip disarticulation. Energy consumption when walking with prosthesis and when propelling a wheelchair, each at the respective comfortable movement speed, was measured by means of a portable telemetric system. RESULTS The average comfortable movement speed for prosthetic walking was 30.5 m/min, which was much slower than the 63.1 m/min average for wheelchair locomotion (P < 0.01). The average oxygen cost value for prosthetic walking was 0.639 ml/kg/m, and the average for wheelchair locomotion was 0.175 ml/kg/m, indicating that oxygen cost was significantly higher for prosthetic walking than for wheelchair locomotion (P < 0.01). CONCLUSIONS The results of this research clearly showed that the efficiency of prosthetic walking for elderly hip disarticulation amputees was very low. When the subject is judged not to be a candidate for practical prosthetic walking after a careful multidisciplinary evaluation, wheelchair locomotion may be an alternative to prosthetic walking as a realistic goal.