The relative influence of genetic and environmental determinants on bone mass is still unclear. Using an original multicentric mode of recruitment, based on absorptiometry current practice, the hypothesis of a familial predisposition to low bone mineral content was assessed. The study was based on dual-energy X-ray absorptiometry (DXA) measurements of lumbar and femoral neck bone mineral density (BMD), using daughters of women with a low BMD (case mothers). These BMD values were compared with those of control daughters of women with a normal BMD. Case mothers (n = 72) aged 54.3 +/- 4.8 years were recruited on the basis of a questionnaire and a vertebral Z-score < -2 SD. Their healthy daughters of more than 20 years (n = 77) aged 28.2 +/- 4.9 years had their vertebral and femoral BMD Z-score determined. The control groups were composed of mothers aged 54.1 +/- 4.7 years, paired by age +/- 2 years to the case mothers, and of their daughters of more than 20 years old, aged 27.7 +/- 5.8 years. For daughters, a significant difference was found between the mean vertebral Z-scores (-0.82 +/- 1.08 for cases and 0.01 +/- 1.14 for controls, p < 0.0001). The difference was in the same direction but was not statistically significant for mean femoral Z-scores (-0.58 +/- 1.15 for cases and -0.22 +/- 1.33 for controls, p < 0.073). These findings confirm the hypothesis of a familial predisposition to low BMD.