Premature ovarian failure (POF) is a cessation in the normal functioning of the ovaries in a woman younger than age 40 years. The most common first symptom of premature ovarian failure (POF) is irregular periods. Primary POF can occur in women of any age, even below the age of 20. Chromosome abnormalities of POF include X chromosome, Down syndrome and BEPS (benign edematous polysynovitis) syndrome. Untreated they are associated with an increased risk of osteoporosis, cardiovascular disease, dementia and Parkinsonism. Secondary POF is becoming more important as survival after the treatment of malignancy continues to improve. The causes of secondary POF includes: chemotherapy and radiotherapy, bilateral oophorectomy, and uterine artery embolization. A number of ovarian reserve tests have been designed to determine oocyte reserve and quality. Oestrogen replacement therapy is the mainstay of treatment for women with POF.