Premature ovarian failure is a relatively common condition that affects 1–3% of adult women. Premature ovarian failure occurs when there is loss of ovarian function in women younger than 40 years of age. The causes are mostly iatrogenic or idiopathic. Amenorrhea and infertility are the most important clinical manifestations. So far, no therapeutic intervention has been proved effective in restoring fertility in patients with premature ovarian failure. Attempts to stimulate ovarian function through hormone manipulation typically prove unsuccessful, and patients usually resort to egg donation to achieve pregnancy. In our preclinical work, intraovarian administration of human bone marrow–derived mesenchymal stem cells was able to restore ovarian hormone production, reactivate folliculogenesis, and reverse infertility in a chemotherapy-induced ovarian failure mouse model.