McCune-Albright syndrome (MAS) is characterized by gonadotropin-independent precocious puberty, café-au-lait spots on the skin and polyostotic fibrous dysplasia of bones. Treatment of precocious puberty (PP) in MAS should be considered in patients with poor predicted adult height (PAH). Treatment of gonadotropin-independent PP in MAS with ketoconazole, cyproterone acetate or testolactone, an aromatase inhibitor, does not appear to be always effective in slowing bon. maturation. We report here a Thai girl with MAS who received tamoxifen, one of the selective estrogen receptor modulators, for the management of advanced puberty and rapid bone maturation. Her pubertal progression, vaginal bleeding, growth rate and PAH improved during treatment with tamoxifen despite persistently elevated serum estradiol levels and an enlarged ovarian cyst.