Gastrointestinal stromal tumour (GIST) represents the most common kind of mesenchymal tumour that arises from the alimentary tract. GIST is currently defined as a gastrointestinal tract mesenchymal tumour containing spindle cells (or less commonly epithelioid cells or rarely both) and showing CD117 (c-kit protein) positivity. Targeted molecular therapy of non-resectable GIST using imatinib, a specific tyrosine kinase receptor inhibitor, represents a real milestone in the management of solid malignancy. Imaging studies, both anatomical and functional, are playing an increasingly important role in management of patients with GIST. This review illustrates the radiological appearance of GISTs and the site-specific roles of each imaging tool. Clinical features and radiological differential diagnosis of GIST are also discussed.