Chronic anovulation, polycystic ovarian morphology and hyperandrogenism are the diagnostic criteria for polycystic ovary syndrome (PCOS). Metabolic disturbances are more common in PCOS women who are prone to develop metabolic syndrome and to present higher levels of some cardiovascular disease risk marker. Oral contraceptives are widely used in PCOS, but conflicting data have been reported regarding their impact on carbohydrate and lipid metabolism on PCOS women. This paper presents a critical evaluation of combined oral contraceptives (COCs) metabolic effect - carbohydrate metabolism and insulin sensitivity, lipid metabolism, haemostasis, body weight, arterial pressure and cardiovascular impact - on PCOS women. Because of the paucity of data on the impact of COCs on cardiovascular and metabolic parameters in PCOS patients, most of there commendations are based on studies involving ovulatory women. The use of low-dose COCs is preferable in PCOS, especially among patients with glucose intolerance, insulin resistance and uncomplicated diabetes mellitus. Although reported as a side effect of COCs, marked weight gain has not been confirmed among users. However, when arterial hypertension or elevated risk for thromboembolism is present, progestogen-only hormonal contraceptives should be used instead of COCs. Regarding dyslipidaemia, COCs reduce low-density lipoprotein and total cholesterol and elevate high-density lipoprotein and triglycerides, and therefore are not recommended for women with high triglycerides levels. The choice of a COC, which alleviates the PCOS-induced hyperandrogenism without significant negative impact on cardiovascular risk, is one of the greatest challenges faced by gynaecologists nowadays.