The ovary is a multipurposemulti-purpose organ, a well organised composite of germ cells and somatic cells, whose interactions dictate the formation of oocyte-containing follicles which is, the fundamental reproductive unit underlying female fertility. The ovary harbours, nurtures, and guides the development of the oocyte so that when it is expelled from the ovary, it has been fully prepared for its migration down the fallopian tube, its fertilization, and its eventual implantation in the wall of the uterus. Additionally, the ovary is an endocrine organ. It provides the steroid and protein hormones essential for the onset of menstruation and its cyclical perpetuation, as well as transforming a prepubertalpre-pubertal girl into a mature woman. Many events in the adult ovary are controlled by two hormones, follicle stimulating hormone (FSH) and luteinising hormone (LH) secreted from the anterior pituitary gland under the control of gonodatropin releasing hormone (GnRH) from the hypothalamus. The ovarian function depends on a highly orchestrated chain of endocrine events involving multiple organ systems. Disruption of this orchastrated network can lead to many clinical syndromes including premature ovarian failure, polycystic ovarian syndrome, ovarian hyperstimulation syndrome, ovulation defects, poor ovarian reserve, and ovarian cancer.