A case control study was carried out in the Orthopaedic Department of Bradford Royal Infirmary in an attempt to see if certain medical conditions, which can affect balance and stability, are more common in those who sustain a second proximal femoral fracture. Medical conditions included in the study were: late effects of cerebro-vascular accident, blindness, syncope and collapse, alcoholism, Alzheimer's disease, epilepsy, Parkinsonism, ischaemic heart disease and senile dementia. The study group comprised 53 patients admitted to hospital between 1992 and 1998 with two separate proximal femoral fractures each on a different side. The control group comprised 530 patients selected from a general pool of 2080 proximal femoral fracture patients admitted to hospital during the same period. The control group patients were matched to the study group for age, sex, and time of occurrence of the first fracture. Results show significantly higher association of late effects of cerebro-vascular accident, blindness, syncope and collapse, and Alzheimer's disease with subsequent contralateral proximal femoral fractures. This study supports a causal relationship between the above medical conditions and subsequent contralateral proximal femoral fractures. It may therefore be possible to identify patients who are at risk of returning with a second fracture.