The experience of St Bartholomew’s Hospital in the treatment of acromegaly with octreotide is presented. When administered intravenously and subcutaneously, octreotide had a longer circulating half-life than natural somatostatin. Subcutaneous octreotide in a range of doses (50-400 µg) caused a very similar degree of growth hormone (GH) suppression, but the duration of suppression increased with size of dose. A dose of 100 µg octreotide 8-hourly provided very good suppression of GH in acromegalic patients; occasional nocturnal escapes may be a problem of inadequate dosage. Long-term octreotide treatment in 14 patients reduced GH to below 20 mU/1 and only 1 case was apparently unresponsive. No serious side effects have so far been seen. Octreotide antibodies have been detected in 1 patient unresponsive to octreotide infusion. Gallstones have been found in 6 of 14 patients.