Polycystic ovary syndrome (PCOS) is a complex disorder affecting a substantial group of women from adolescent to menopausal age groups. A substantial subgroup of these women exhibits increased insulin resistance. Insulin resistance is difficult to establish in clinical practice and many surrogate tests are available, although their value in the clinical setting is uncertain. The QUICKI method is an inexpensive and easy test to administer and is probably the best test to be used in PCOS patients, preferably in a clinical trial context. There is considerable evidence that insulin-sensitizing agents are not contributory to infertility management in the majority of women with PCOS. Currently, there is no evidence that cardiovascular morbidity is decreased by long-term use of insulin sensitizers in PCOS women.