Gastrointestinal stromal tumors (GIST) are rare mesenchimal neoplasmas of the gastrointestinal tract. The diagnosis of this tumors are oftenly very difficult. Patients with this tumor are ussualy addmited to the hospital cause of the gastrointestinal bleeding, abdominal pain, abdominal distension, disphagia, obstructive jaundice and bowel obsstruction. In this case report, we present a 86 year old patient with massive GIST of the stomach which was not preoperatively diagnosed.