The authors present the case of a 60 year-old man known for a rectal polyp which was diagnosed in 1994 and since then followed-up by means of a colonoscopy associated with periodic biopsies. Recently, the results of a biopsy revealed positive markers for the diagnosis of Gastro-Intestinal Stromal Tumor (GIST). Despite the absence of malignant criteria, an anterior resection of the rectum was performed by laparoscopy and the patient rapidly recovered. Epidemiology, diagnosis and management of this rare location of GIST's are discussed.