The onset of pubertal development before the age of 8 years in girls or 9 years in boys constitutes precocious puberty. There are numerous causes of precocious puberty, which can be classified as central or peripheral precocious puberty. Central precocious puberty results from premature activation of the hypothalamic-pituitary-gonadal axis and thus presents with physical and hormonal findings similar to those found in normal puberty. Peripheral precocious puberty results from extrapituitary gonadotropin secretion or secretion of sex steroids independent of pituitary gonadotropins. All types of precocious puberty are characterized by rapid growth and advancement of skeletal age, leading to the paradox of the tall child becoming a short adult as a result of premature epiphyseal fusion. Long-acting GnRH agonists afford effective, selective, and reversible therapy of central precocious puberty without significant toxicity. GnRH agonists are not effective in managing the premature sexual maturation associated with peripheral precocious puberty, but a number of other agents have been used with some success. These agents include testolactone, ketoconazole, and medroxyprogesterone acetate. GnRH agonist treatment leads to an increase in predicted final height. To determine the true benefit of any of these agents in increasing ultimate height, there is a need for continuing studies in treated cohorts to follow growth patterns until adult stature is achieved.