Qualitative and quantitative differences in the dietary habits of postmenopausal women were studied to assess their influence on bone health and osteoporosis. A total of 194 postmenopausal women were studied with forearm DEXA densitometry. 70 were osteoporotic and 124 served as controls. Women had been menopausal for 5-7 years, and had never been treated with hormone replacement or drug therapy. A 3-day dietary recall was completed on Sunday, Monday and Tuesday after the examination: the results were processed by computer and daily calcium, phosphorus and magnesium intakes were related to bone mineral content (BMC). Data were compared with Student's t-test and significance was assessed at p < 0.05. Regression analysis was performed to correlate BMC and intake levels. The dietary intake of calcium, phosphorus and magnesium was significantly reduced in osteoporotic women and correlated with BMC. Calcium and magnesium intakes were lower than the recommended daily allowance even in normal women. The results suggest that nutritional factors are relevant to bone health in postmenopausal women, and dietary supplementation may be indicated for the prophylaxis of osteoporosis. Adequate nutritional recommendations and supplements should be given before the menopause, and dietary evaluation should be mandatory in treating postmenopausal osteoporosis.