The failure of ovarian development occurs when the ovaries fail to develop according to developmental age and lose or disrupt their normal functions. Ovaries are female reproductive organs that are responsible for the development of oocyte (ovum) for reproduction. It also produces hormones such as estrogen and progesterone that control the menstrual cycle in women. Failure of ovarian development can be due to primary ovarian insufficiency where the cause is usually unknown or could be due to genetic factors, autoimmune disease, infections or toxins. It can also be a secondary ovarian failure caused by different types of good or bad tumours in the brain such as prolactinoma, pituitary adenoma, hypothalamic tumour, metabolic disorders such as Cushing syndrome, severe eating disorders, stress, and certain medications. Failure of ovarian development leads to signs and symptoms such as irregular menstrual cycle or absence of period, hot flushes, night sweats, decreased sexual desire, irritability, mood swings, poor concentration, and vaginal dryness. This condition can eventually lead to complications such as infertility, osteoporosis, depression, and anxiety. It can be diagnosed by ultrasound, follicle-stimulating test, estradiol test, prolactin test, karyotype and MRI of the pituitary and hypothalamus conducted and interpreted by your treating doctor. The most common treatment is long term hormone replacement therapy.