Precocious puberty can be distinguished in central, or peripheral, based on the presence or absence of the Hypothalamic- Pituitary- Gonadal axis activation. The pathogenesis of peripheral precocious puberty (PPP) is based mainly on excessive estrogenic exposure, either endogenous or exogenous. The congenital causes of PPP include McCune- Albright syndrome (MAS) and Congenital Adrenal Hyperplasia (CAH). The main causes of acquired PPP are oestrogen producing tumours, which are mainly of ovarian or adrenal origin, hypothyroidism and environmental oestrogens or substances with estrogenic function.