Six girls and one boy with precocious puberty were treated with a superactive LHRH analogue (D-TRP6-LHRH) for periods ranging from 1 year to 2 years and 3 months. In the first phase of the treatment it was administered in combination with cyproterone acetate (CyA) to counteract an early stimulatory effect until inhibition of gonadotrophin secretion was achieved. The gonadotrophin-dependent signs i.e. gonadarche, showed sustained arrest and even regression. Gonadal sex steroids decreased but the adrenal androgens were unaffected. In four patients who showed progression of the angrogen-dependent signs (adrenarche), despite suppression of gonadotrophins, increasing the dosage of the LHRH analogue was ineffective and combined therapy with CyA was reinstituted in three of them because of accelerated growth and bone maturation. It is concluded that at present the treatment of choice for precocious puberty is the daily administration of a superactive LHRH analogue such as D-TRP6-LHRH, together with CyA in the initial stage, and at a later state if adrenarche progresses too rapidly.