Background: the impact of anaemia on the outcome after a hip fracture surgery is controversial, but anaemia can potentially decrease the physical performance and thereby impede post-operative rehabilitation. We therefore conducted a prospective study to establish whether anaemia affected functional mobility in the early post-operative phase after a hip fracture surgery. Patients and Methods: four hundred and eighty seven consecutive hip fracture patients, treated according to a well-defined multimodal rehabilitation programme with a uniform, liberal transfusion threshold, were studied. Hb was measured on each of the first three post-operative days, and anaemia defined as Hb Results: the results were obtained from 170, 132 and 116 patients who were found anaemic on the first, second and third post-operative day, respectively. A significant association between anaemia and the ability to walk independently before the correction of anaemia was present on each of the 3 days separately ( P P = 0.002]. Conclusion: anaemia impedes functional mobility in the early post-operative phase after a hip fracture surgery and is an independent risk factor for patients not being able to walk post-operatively. The potential for a liberal transfusion policy to improve the rehabilitation potential in hip fracture patients with anaemia should be investigated.