It is recommended to follow the Rotterdam criteria for the diagnosis of PCOS (meeting two of the following criteria: androgen excess, ovulatory dysfunction, or polycystic ovarian changes). For adolescent and menopausal women, the diagnosis of PCOS cannot be established. The main manifestations of PCOS in adolescent women include hyperandrogenism, whereas the corresponding manifestations are lacking in menopausal women. For women undergoing PCOS-related evaluation, alternating hyperandrogenic disorders should be excluded, as well as risk factors associated with endometrial cancer, mood disorders, obstructive sleep apnea, diabetes mellitus, and cardiovascular disease. Hormonal contraceptives should be the treatment of choice for menstrual abnormalities and hirsutism/acne associated with PCOS. Currently, clomiphene is the drug of choice for infertility; metformin has benefit for metabolic/glycemic abnormalities and helps improve menstrual irregularities, but is not effective for hirsutism, acne, or infertility. Hormonal contraceptives and metformin may be the drug of choice for patients with adolescent PCOS. For PCOS itself, the role of weight reduction remains unclear, but other health benefits of lifestyle interventions exist for overweight/obese patients. The overall risk-benefit ratio for thiazolidinediones is not superior, and the role of statins still needs to be confirmed by further studies.