In acromegaly, the overproduction of growth hormone is usually caused by a pituitary adenoma. We report a 74-year-old woman with acromegaly caused by ectopic overproduction of growth hormone-releasing hormone (GHRH), a rare diagnosis. The GHRH appeared to be produced by a carcinoid tumour of the lung. Treatment with monthly long-acting octreotide resulted in a reduction in the symptoms and normalisation of the insulin-like growth factor-I, which has been maintained for more than two years now. A review of literature concerning causes and treatment of ectopic GHRH-producing tumours is presented.