Ten patients, aged 5 to 20 years, with short stature were given l-DOPA orally to assess its effects on pituitary hormone secretion. The group included seven children with constitutional short stature, one with isolated HGH deficiency and two with idiopathic hypopituitarism. Doses of l-DOPA ranged between 200 and 500 mg. Six of the seven constitutionally short children responded with elevations in HGH concentration above 7 ng/ml, peak levels occurring between 30 and 120 min after drug administration. No HGH release was observed in the individual with isolated HGH deficiency or the subjects with idiopathic hypopituitarism. No effects were seen on the plasma concentrations of FSH, LH, TSH and cortisol in the five endocrinologically normal patients in whom they were measured.