The aim of this study was to study bone turnover and density in postmenopoausal women. One hundred healthy postmenopausal women aged 45 to 86 years, in whom menopause occurred between 3 months and 33 years before and were not receiving medications that could alter bone metabolism, were studied. Measurements performed were serum alkaline phosphatases, urine hydroxyproline/creatinine and calcium/creatinine excretion ratios and lumbar spine and femoral bone densities. Mean urinary hydroxyproline/creatinine excretion ratio was 39.5 +/- 11.9 (over 45 in 26% of women) and calcium/creatinine ratio was 0.11 +/- 0.08 (over 0.12 in 29% of women). At least one of these measurements were increased in 39% of women and no relationship of these values with age or length of postmenopausal period was found. Alkaline phospatases were elevated in 9.6% of women. Twenty six percent of women had lumbar spine osteopenia and 10% femoral neck osteopenia. There was an inverse relationship between the length of hypoestrogenism and bone density. ft is concluded that more than one third of studied women had biochemical evidences of bone resorption and that these women had a higher frequency of osteopenia than the general population. A decrease in bone density and an increase in bone resorption indices identify women with higher risk of osteoporosis that could be benefitted with an opportune treatment.