After previous demonstration of paradoxical GH responses to TRH and oral glucose loading tests in some constitutionally tall adolescents, we studied the effects of a small dose of bromocriptine (5 mg/day) on GH secretion and adult height prediction. In 10 patients, each of whom had a substantial plasma GH increase after TRH injection, bromocriptine reduced or suppressed this abnormal response. In 4 of these patients who also had paradoxical GH increases after glucose loading, bromocriptine suppressed this abnormality in 2. Predicted adult height was reduced in 10 of the 12 patients after 6-12 months of treatment. This reduction resulted either from a decrease in growth velocity, an increase in skeletal maturation rate, or both. Since no side effects were noticed we suggest that bromocriptine may be a valuable alternative to sex steroid treatment to limit final height in excessively tall adolescents.