Somatostatin analogue scintigraphy represents a new technique employing radiolabelled peptides to detect specific receptor-bearing lesions. 111Indium diethylene-triaminopentaacetic acid-linked octreotide (111In-DTPA-D-Phe1-octreotide), also known as [111In]pentetreotide or OctreoScan, is now established in the management of patients with neueroendocrine gastrointestinal tract and pancreatic tumours, and has proved effective in localizing disease sites in lung, breast and medullary thyroid carcinomas, lymphomas, meningiomas and others. In these conditions (a) the imaging of all disease sites at a single sitting (in a proportion of patients) thereby making further investigations unnecessary, (b) the localization of otherwise unexpected metastatic deposits and (c) the detection of residual disease not found by other means suggest that [111In]pentetreotide may be a useful adjunct in the diagnostic evaluation of patients with somatostatin receptor-bearing tumours.