OBJECTIVE We evaluated bone loss in women during the peri and post-menopausal period in order to determine the exact effect of menopause on vertebral bone density and biochemical markers of bone remodelling. METHODS One hundred fifty-seven women who consulted for menopause and who did not wish to receive substitution therapy were enrolled. Menopause was defined as amenorrhoea > or = 1 year and serum 17-beta oestradiol < or = 20 pg/ml and luteinizing hormone > 30 IU/ml. Precocious or surgical menopauses were excluded. Two groups were formed according to the hormone pattern: a peri-menopausal group (n = 32, mean age 51.2 +/- 2.9 years) and a post-menopausal group (n = 125, mean age 54.3 +/- 3.7, menopause 1 to 11 years at entry). Bone density was measured by biphonotonic absorptiometry and blood chemistry was performed with routine laboratory methods. All tests were repeated at successive consultations and mean follow-up was 32 +/- 12 months. RESULTS Annual rate of bone loss was during peri-menopause (-1.8 +/- 1.7%) and the first 4 years of menopause (-1.6 +/- 1.6%), then decreased significantly beyond 4 years. Mean bone loss from 5 to 10 years menopause (-0.60 +/- 1%). Initial serum calcium, phosphorus, alkaline phosphatase and osteocalcine levels were significantly higher during post-menopause than during peri-menopause (P < 0.05). The urinary calcium/creatinine ratio was comparable between the two periods and decrease after 4 years of menopause. CONCLUSIONS This longitudinal study indicated that increased vertebral bone loss begins early during peri-menopause and is temporary since it does not continue beyond 5 years. It is important to consider these findings when developing strategy for the prevention of menopausal osteoporosis.