Patients with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) can be classified as types 1 or 2, according to the presence or not of ovarian failure. We report a 5 year-old girl with BPES and large multicystic ovaries who developed peripheral precocious puberty with thelarche (Tanner stage III) and pubarche (Tanner stage II). Pelvic ultrasound revealed pubertal uterus and enlarged multicystic ovaries. Fibrous dysplasia and McCune-Albright syndrome were ruled out. Treatment with an estrogen antagonist was started (tamoxifen, 10 mg/day), achieving regression of thelarche. Tamoxifen treatment was stopped at 10-(7/12) years, and growth velocity and skeletal maturation rate returned to normal. No treatment-associated adverse effects were observed.