Somatostatin, a naturally occurring 14-amino acid peptide, can be thought of as an anti-growth hormone and functional down-regulator of sensitive tissue. Most neuroendocrine tumors seem to possess somatostatin receptors in sufficient abundance to allow successful scintigraphic imaging with radiolabeled somatostatin congeners. Several of these, including Indium-111-DTPA Pentetreotide (Octreoscan [Mallinckrodt Medical, St. Louis, MO]), which was approved for clinical use by the Food and Drug Administration in June 1994, have been of considerable value in scintigraphically identifying various neuroendocrine tumors. The Octreoscan compares favorably with other imaging modalities. The success of somatostatin receptor imaging in evaluating patients with suspected neuroendocrine tumors, including identifying otherwise radiographically occult lesions, has resulted in ranking somatostatin receptor imaging as the prime imaging procedure in patients with suspected neuroendocrine tumors at The Ohio State University.