This prospective randomized, single-blind, placebo-controlled clinical trial was performed to evaluate the efficacy of raloxifene in preventing the bone loss associated with GnRH agonist (GnRH-a) administration. One hundred premenopausal women with uterine leiomyomas were treated with leuprolide acetate depot at a dosage of 3.75 mg/d for 28 d and then randomized into two groups to receive raloxifene hydrochloride at 60 mg/d (group A) or placebo (1 tablet/d; group B). Bone mineral density (BMD) and serum bone metabolism markers were evaluated at admission and after six treatment cycles. Posttreatment BMD differed significantly from baseline BMD in group B but not in group A. BMD was significantly higher in group A than in group B. In group A, serum osteocalcin and bone alkaline phosphatase levels and urinary deoxypyridinoline and pyrilinks-D excretion were unchanged vs. baseline. Differently, posttreatment concentrations of these bone turnover markers were significantly lower in group B compared with baseline and group A values. In conclusion, raloxifene prevents GnRH-a related bone loss in premenopausal women with uterine leiomyomas.