Abstract: GISTs account for approximately 80% of gastrointestinal mesenchymal tumours. The literature about GIST remains confusing because tumour classification and terminology are continually refined. Furthermore, the exact definition of GIST varies among authors. Mostly occur in the stomach and small intestine with rare occurrence in the rectum (5%), colon (1%), oesophagus and appendix. The diagnosis of GIST is currently based on morphologic features and immunohistochemical demonstration of KIT (CD 117). Early resection is treatment of choice. STI-571 (Imatinib), a KIT tyrosine kinase inhibitor has recently shown promise in the treatment of metastatic GISTs. The three key prognostic factors have been mitotic rate, tumour size and site. The five year survival rate declines and prognosis becomes poor with increase in the size and mitotic activity.