Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract and are defined by their expression of KIT (CD117). This article includes 109 pathologically proven GISTs, with emphasis on their various computed tomography (CT) features. Although the images of GISTs on the CT scan are often distinct from those of epithelial tumors, radiologists should be familiar with these features for the accurate diagnosis of GISTs.