Abstract: Premature adrenarche is characterized by an early increase in adrenal androgen production that results in the development of pubic hair before the age of 8 years in girls and 9 years in boys, with or without axillary hair, and with no other signs of sexual development. Premature adrenarche has no adverse effects on the onset and progression of gonadarche and final height. However, it can no longer be considered a benign condition as it has been associated with hyperinsulinemia, dyslipidemia, and obesity already in the prepubertal period and polycystic ovary syndrome (PCOS) at adolescence. Furthermore, a possible association between premature adrenarche and metabolic and endocrine abnormalities with low birth weight has been postulated. PCOS, as recently redefined, is the most common endocrine disorder to affect women of reproductive age and has been associated with increased risk for type 2 diabetes and increased prevalence of cardiovascular risk factors at an earlier age than expected. Premature adrenarche and PCOS share similar metabolic disturbances. It may be that metabolic abnormalities start very early in life during the prenatal or prepubertal period and premature adrenarche may be a forerunner of PCOS and the metabolic syndrome in some girls. Large long-term epidemiological studies are needed to allow clear association of the two conditions and assessment of the risk of disease in later life.