Intracranial lesions may affect hypothalamic-pituitary (HP) function and growth in several ways, depending on the location of the lesion within this area, the presence or absence of secondary hydrocephalus, and/or treatment of the lesion by surgery and/or radiotherapy. The lesion may cause a deficiency of HP hormones or, conversely, activation of the HP-gonadal axis leading to precocious puberty. Growth hormone (GH) deficiency is the most frequent endocrine abnormality that results from the lesions of the HP area. There has been progress in diagnosis, patterns of replacement therapy and the administration of biosynthetic GH in association with gonadotropin-releasing hormone analogues in precocious puberty. The major problem in these patients is the dramatic increase in their weight, which frequently occurs after surgery and increases their psychosocial and physical disabilities. It may be due to the hyperinsulinism caused by the lesion. This hyperinsulinism may be the factor that replaces GH in stimulating growth factor production and leads to normal growth in some of the patients.