Disorders of puberty can profoundly impact physical and psychosocial well-being. Precocious puberty is pubertal onset before eight years of age in girls and before nine years of age in boys. Patients with early isolated pubertal changes, prepubertal linear growth, and no worrisome neurologic symptoms typically have a benign pattern of development and should be monitored in the appropriate clinical context. Among patients with true precocious puberty, or full activation of the hypothalamic-pituitary-gonadal axis, most girls have an idiopathic etiology, whereas it is commonly due to identifiable pathology on imaging in boys.