Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract. These tumors span a wide clinical spectrum from benign to malignant and have long been recognized for their nearly absolute resistance to chemotherapy and radiation treatment. We reviewed the worldwide experience on GIST diagnosis, prognosis and treatment and describe our own series. PubMed was searched for references using the terms gastrointestinal stromal tumor, GIST and gastrointestinal sarcoma. Recent reports were given emphasis because GIST is a novel clinical entity and older published work on gastrointestinal sarcomas might be contaminated with other histologic tumor types. At present, surgery is the standard treatment for primary resectable GIST. To increase the activity of conventional chemotherapeutic agents, locoregional therapies are being implemented in the clinical setting. A major breakthrough is the development of a new class of anticancer agents targeting tumor-specific molecular abnormalities. Preliminary results on administration of imatinib mesylate, a signal transduction inhibitor, are particularly encouraging, showing potent activity of this drug against metastatic GIST. Molecular targeting of the critical pathogenetic mechanism underlying GIST might not only revolutionize the strategy to treat locally advanced and metastatic GIST but also improve disease control after macroscopically radical surgery. Copyright 2003 Wiley-Liss, Inc.