Octreotide usually induces long-acting inhibition of GH secretion without rebound hypersecretion. We report a patient with acromegaly who showed rebound elevation of GH and insulin-like growth factor-1 (IGF-1) after octreotide withdrawal. The patient responded remarkably to octreotide therapy with normalization of GH and IGF-1 and shrinkage of pituitary macroadenoma. Octreotide therapy was stopped when he developed liver dysfunction. GH and IGF-1 were markedly elevated for two weeks after cessation of octreotide.