Ninety-seven elderly patients with acute fractures of the proximal femur sustained as a result of minimal trauma were studied with regard to variables that may potentially influence the incidence or outcome of fractures of the proximal femur. The mean bone mineral density (BMD) measured at the femoral neck was approximately 2 SDs below age- and sex-adjusted normals. There was a preferential loss of bone mineral from the femoral neck in younger patients with hip fractures (Z score -3.10 +/- 0.23) (mean +/- SEM) compared with the lumbar spine (Z score -1.71 +/- 0.41). Mean daily calcium intake was well below the recommended levels and calcium intake < 400 mg/day was associated with lower lumbar spine BMD Z scores (p = 0.01). Ambulatory ability was unassociated with BMD Z scores. The results of this study suggest that the femoral neck is a site of preferential bone loss in younger postmenopausal patients, and screening of patients at risk of hip fracture should measure BMD at this site. Calcium supplementation may play a role in decreasing the incidence of hip fractures.