The clinical symptoms of the variety of syndromes associated with islet cell tumors are described. Islet cell tumors have the potential to excrete a variety of endogenous and exogenous hormones and consequently a variety of clinical syndromes result. Case reports of patients with Zollinger-Ellison, WDHA, insulinoma, and glucagon secreting tumors are presented. The Z.E. and WDHA syndromes are primarily gastrointestinal syndromes and the radiologist plays a pivotal role in establishing the diagnosis of these patients. In the glucose relating tumors, the insulinomas and glucagonomas, the main role of the radiologist is in confirming clinical impression and localizing the lesion. Early diagnosis is important because all these tumors are potentially malignant and cure can only be achieved if they are detected prior to the dissemination of metastases.