The aim of this study was to assess lumbar spine bone density in a group of chilean postmenopausal females and to estimate the frequency of vertebral osteopenia in the national urban female population. A clinical assessment and lumbar spine bone density measurement were performed to 171 healthy women over 40 years of age and not receiving medications that modify bone turnover. Calcium ingestion was recalled in 77 of these. Fifty women (29.2%) had osteopenia, defined as a bone density of less than 0.92 g/cm2. Extrapolating this figure to the national urban population, an osteopenia frequency of 21.7% was estimated. Body mass index was 25.5 +/- 3.8 and 57% of the sample was overweight. Calcium ingestion was 740.3 +/- 331.7. These two parameters did not correlative with bone density. Women with osteopenia were older and had a longer postmenopausal lapse than those with normal bone density. The completion of further clinical an epidemiological studies is recommended to know the real magnitude of osteoporosis in Chile.