Aim of the study: The recently introduced new nosological category, Gastro Intestinal Stromal Tumors, brought the Authors to a revision of their series and to a critical analysis of surgical behaviour for the treatment of that pathology. Material and method: A series of 23 cases of GIST, observed between 1977 and 1999 has been taken into account. In the earlier cases, histopathological classification has been reviewed according to the most used criterions in international scientific literature. Results: 17 of 23 observed tumors were located on the stomach, 4 on the duodenum and 2 on the jejunum. 20 of these cases derived from muscular tissue and 3 cases derived both from muscular and neural tissues. In 7 cases (30%) tumors were accidentally discovered during surgical intervention or diagnostic procedures for other causes. Surgical treatment was performed in all cases and consisted in 6 gastric resections, 14 gastric free-margin excisions, 2 duodenal resections and 1 jejunal resection. The follow-up (performed on 18 patients, with a minimum of 1 year, a maximum of 17 years and a median of 6 years) showed 2 deaths (11%) due to oncological causes, while 2 of the patients (11%) died for other causes. Conclusions: The only treatment for that group of tumors is, at the moment, surgery. Although that kind of neoplasms has mainly non-aggressive biological behaviour, a radical resection must be performed, due to the absence of macroscopic criterions to help distinguishing, during surgical intervention, aggressive tumors from non-aggressive ones.