Surface cells in adult ovaries represent germ line-competent embryonic stem cells. They are a novel type of totipotent progenitors for distinct cell types including female germ cells/oocytes, with the potential for use in the autologous treatment of ovarian infertility and stem cell therapy. Ovarian infertility and stem cell therapy are complex scientific, therapeutic, and socioeconomic issues, which are accompanied by legal restrictions in many developed countries. We have described the differentiation of distinct cell types and the production of new eggs in cultures derived from adult human ovaries. The possibility of producing new eggs from ovarian surface epithelium representing totipotent stem cells supports new opportunities for the treatment of premature ovarian failure, whether idiopathic or after cytostatic chemotherapy treatment, as well as infertility associated with aged primary follicles, and infertility after natural menopause. The stem cells derived from adult human ovaries can also be used for stem cell research and to direct autologous stem cell therapy. This chapter describes general considerations regarding the egg origin from somatic progenitor cells, oogenesis and follicle formation in fetal and adult human ovaries (follicular renewal), including the promotional role of the immune system-related cells in vivo, and possible causes of ovarian infertility. It then provides detailed protocols for the separation and cultivation of adult ovarian stem cells.