BACKGROUND: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract. The majority of GISTs are located in the stomach. Only 3-5% of GISTs are located in the duodenum associated with an increased risk of gastrointestinal bleeding as primary manifestation. AIM: The aim of our study was to present frequencies of GIST in patients who underwent endoscopic procedures at Gastroenterohepatology Department due to different reasons. We also investigated the most frequent localization of GIST tumors and pathohistologicall pattern of tissue samples. PATIENTS AND METHODS: Twenty two patients examined at gastroenterology department were analyzed in the period from 2005 until 2012. All of the patients were endoscopically examined ( gastroscopy, colonoscopy, endoscopic ultrasound). A few patients were referred from surgery where GIST was diagnosed during surgical procedure. Macroscopically noticed changes were pathohistologically analyzed by immunohistochemical staining (Alpha-smooth muscle actin (SMA), CD34, CD117, Ki-67 antigen, cytokeratin i desmin). RESULTS: No significant difference in gender distribution of patients with GIST-s was found. We also analyzed the appearance of GIST with respect to mean patient age and no statistically significant difference was found either. However, investigation of tumor localization related to gender of patients we found a difference in gender distribution of tumor localization. In female GIST-s are more often located in the stomach than in men, with a significance level of 0.05. Immunohistochemical analysis of biopsy samples showed that CD 117 is statistically significant more frequent in men than in woman. CONCLUSION: Taking in account the small sample size in our investigation over a period of seven years, we are not able to give a definitive conclusion about GIST. Further studies and observations are necessary to give a definite conclusion.