Lumbar spine and proximal femoral bone densities of Caucasian women, aged 35-45, were measured by dual photon densitometry model DPX. The measurement sites were assessed at the lumbar spine (vertebrae L2 to L4) and at the proximal femur (trochanter, femoral neck and Ward's triangle). After exclusion of women with climacteric symptoms, sterilized patients or those with menopausal concentrations of gonadotrophins, the study included 22 subjects: 11 menstruant (control group) and 11 hysterectomized. The hysterectomies were without oophorectomy and had been performed during the previous five years. The bone densities of the hysterectomized women were lower than those of the normal ones, but significantly lower at the Ward's triangle.