A decrease in bone mineral density has been reported to be associated with increased progression of aortic stenosis (AS). We hypothesized that osteoporosis treatment (OT) is associated with decreased progression of AS. We performed an observational study of patients with AS from our echocardiographic database comparing 18 patients on OT (bisphosphonates, calcitonin, or estrogen receptor modulators) with 37 patients not on OT. All patients had serial echocardiograms. Patients with mitral stenosis, aortic valve replacement, renal failure, calcium disorders, or left ventricular ejection fraction <40% were excluded. Aortic valve area (AVA) was calculated using the continuity equation. There was no significant difference in age, gender, renal function, hypertension, statin use, diabetes, or calcium level between the 2 groups. Mean baseline AVA was 1.33 cm(2) and not significantly different between groups. After a mean of 2.4 +/- 1.0 years, mean annual changes in AVA were -0.22 +/- 0.22 cm(2) in those not on OT and -0.10 +/- 0.18 cm(2) in patients receiving OT (p = 0.025). There was a graded association between AS progression rate and OT. In a multivariable analysis including age, gender, and statin use, only OT was associated with a change in AVA. In conclusion, OT is strongly and independently associated with decreased progression of AS. This association warrants investigation in a larger, prospective study.