Medical management of Nelson's syndrome by drugs such as bromocriptine, sodium and magnesium valproate has provided disappointing or, at least, controversial results. We report here on the results of long-term (2 yr) treatment with the somatostatin analogue octreotide (300 micrograms daily sc) in one patient affected by Nelson's syndrome occurring after bilateral adrenalectomy for Cushing's syndrome. During treatment, skin hyperpigmentation and serum ACTH levels decreased dramatically and a slight (about 10%) reduction in tumor size, as assessed by computerized tomography, was also observed. These results suggest that octreotide may be useful for the medical management of Nelson's syndrome.