Using 153Gd dualphoton absorptiometry, bone mineral density (BMD) was measured in three areas of the proximal femur-the femoral neck, Ward's triangle and the greater trochanter-in 129 females referred for possible osteoporosis. In addition, lumbar spine bone density was determined. Lumbar spine BMD was significantly greater than any regional proximal femoral BMD (p less than 0.0001). Ward's triangle was significantly less than the trochanteric region (p less than 0.01) and both Ward's triangle and the greater trochanter were significantly less than the femoral neck (p less than 0.0005). Correlations within the three regions of the proximal femur are considerably higher than those between the spine and the proximal femur regions. This suggests that measurement of all three areas of the proximal femur is not essential for a satisfactory assessment of proximal femoral mineral content. In particular, since Ward's triangle is strongly correlated with the greater trochanter and the femoral neck, it may rationally be excluded from analysis of proximal femoral bone density.