During a 15-month period, 47 elderly female patients admitted to hospital with a fractured neck of femur were studied immediately prior to discharge, in comparison with 34 elderly female control patients undergoing elective surgery who had been admitted over the same period to the same orthopaedic wards. The principal differences between the two populations were that the fracture patients had a lower forearm trabecular bone density, with lower bodyweight (both lower muscle mass and lower fat content), increased body sway, worse eyesight and reduced mental acuity. The serum biochemistry of the two groups was almost indistinguishable except that the fracture patients tended to have slightly lower concentrations of proteins. There was no evidence to implicate dietary vitamin D deficiency, osteomalacia, oestrogen deficiency or alcoholism in the aetiology of the fracture, nor was there evidence to suggest alterations in endocrine function with respect to calcitonin or parathyroid hormone.