GISTs are rare mesenchymal tumors. Positive diagnosis of these tumors is based on histological examination, coupled with immunohistochemistry. CT is the examination of choice for diagnosis, resectability assessment, post-operative surveillance and evaluation of response to treatment. MRI is the gold standard for the evaluation of rectal GISTs and liver metastases.The aim of this educational book is to provide a histopathological description, illustrate the different presentations and the main imaging features for the diagnosis and post-treatment follow-up of GISTs. The book also aims to discuss the main differential diagnoses and therapeutic options for these tumors.This book is intended for all practicing physicians.