The aim of our study was to evaluate the accuracy of MDCT in the study of gastrointestinal stromal tumour (GIST), and to compare CT results with histological findings.MDCT exams of 18 patients with 19 lesions, with histological proven GISTs diagnosis, were retrospectively evaluated in order to assess the localization, the size, the contours, as well as the CT pattern and enhancement of the lesions. All the tumors were recorded with Fletcher and Miettinen classification, which evaluate the risk assessment in the gastrointestinal stromal tumours. CT findings were correlated with histological results after surgery.MDCT properly identified the localization and the size in all cases. CT features essentially agreed with histological features.The immunopositivity to c-KIT (CD117) is the key to making a diagnosis of GIST. CT is the modality of choice to study these neoplasms, evaluating the tumour's site and size with high accuracy. In our experience MDCT proved to be a valid diagnostic tool, highly correlated with histological features.