Seven children with anterior hypopituitarism and two children with possible isolated growth-hormone deficiency have been treated with injections of human pituitary growth hormone (HGH) for periods of three months to 3 1/2 years. Administration of HGH was planned to demonstrate the minimal dosage and the maximal interval between injections which are efficacious in growth promotion. Weekly injections of 2.5 to 5 mg of HGH usually were effective in achieving normal or accelerated growth velocity for maturational age. Daily injections of one seventh the weekly dose were not effective, nor were single monthly injections of four times the weekly dose. In one patient, biweekly injections of 10 mg were as effective as weekly injections of 5 mg. Diminishing responsiveness with increasing duration of treatment was observed.