A cross-sectional study was designed to determine trabecular bone density in 75 long-term depot-medroxyprogesterone acetate (DMPA) users (> 3 yr) matched with non-DMPA users by age, body mass index (18-25), limitation of age (< 45 yr), and body weight (< 60 kg). The long-term DMPA cases were divided into 3 groups according to duration of injectable contraceptive use. Neither cases nor controls had a smoking or chronic alcohol consumption history. Cases and controls were matched by age. Trabecular bone of the femoral neck were assessed by X-ray and interpreted by a single-blinded radiologist. Trabecular bone patterns were graded according to Singh's Index. Blood collection for determination of estradiol, prolactin, calcium, phosphorus, and medroxyprogesterone acetate were performed in cases and controls. Venous blood was taken at twelfth week of injection of DMPA and within 5 days after menstrual bleeding cessation in the controls. Mean trabecular bone in the cases was 5.5 +/- 0.6 (range 4-6). It was not statistically different from that in the controls (mean 5.5 +/- 0.6, range 2-6). No statistically significant difference of serum, calcium, phosphorus, prolactin, and estradiol was seen in the cases when compared to controls at mid follicular phase of normal menstrual cycle. Serum MPA of individual case at twelfth week of injection was 4.1 +/- 1.1 nmol/l. In conclusion, trabecular bone density in long-term DMPA users were not statistically different from normal menstruating women who have not received injectable DMPA.