OBJECTIVE To evaluate bone mineral density (BMD) and bone metabolism in hypertensive postmenopausal women, and to differentiate the effect of thiazides from that of other antihypertensive agents. METHODS A community-based population of 636 postmenopausal women, 293 with hypertension (160 receiving thiazides, and 133 receiving other antihypertensive treatments), and 343 control women, were evaluated. Serum levels of aminoterminal propeptide of type I collagen (P1NP), C-terminal telopeptide of type I collagen (beta-CTX), 25-hydroxivitamin D, and intact parathyroid hormone were measured by electrochemiluminiscence. BMD was determined by DXA, and heel quantitative ultrasound measurements (QUS) with a gel-coupled device. RESULTS BMD expressed as Z-score was higher in both groups of hypertensive women at all locations. Expressed as g/cm(2), it was also higher in patients on thiazides at femoral neck and lumbar spine. Only in the latter site, differences remained significant after adjusting for potential confounding variables, including BMI. Bone turnover markers were lower in both groups of hypertensive women, although the difference was greater in those on thiazides. After adjusting for potential confounders, differences remained significant only in the thiazide group. CONCLUSIONS Our results add evidence to the idea that thiazides are beneficial to prevent bone loss.