Objective To describe a forearm heterotopic ovarian transplantation technique. Design Case study. Setting Academic medical center. Patient(s) One patient with stage IIIB squamous cell cervical carcinoma and one patient with recurrent benign ovarian cysts. Intervention(s) Preparation of thin ovarian cortical slices and transplantation under the skin of the forearm. Main outcome measure(s) Follicular development and oocyte retrieval; cyclical estradiol (E 2) and progesterone (P 4) production; restoration of serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels to reproductive age range. Result(s) Both patients were menopausal immediately after oophorectomy. The first patient developed a dominant follicle 10 weeks after transplantation, and her gonadotropin levels decreased to nonmenopausal levels. Percutaneous aspiration of ovarian follicles yielded a metaphase I (M-I) oocyte that was matured to metaphase II (M-II). The first patient’s graft was functional for at least 21 months. In the second patient, ovarian follicle development was detected 6 months after transplantation, and periodic menstruation occurred thereafter. Spontaneous ovulation was confirmed by a midluteal increase in her P 4 levels. Menstruation and follicle development continued for more than 2 years after the transplant. Conclusion(s) Heterotopic transplantation of ovarian tissue to the forearm is a simple and promising technique to restore ovarian function in women who become menopausal due to chemotherapy, surgery, or radiation.