Spontaneous gastrojejunal fistula formation is an extremely rare complication of gastric ulcer disease. We report a 77-year old woman who presented with diffuse abdominal pain, weight loss, malaise, nausea, and occasional dark stools. Laboratory tests showed extreme hyposideremic anemia with inflammatory syndrome. In addition, biochemical parameters of malnourishment were presented. Upper endoscopy revealed the patent esophagus along the full length without any pathological changes. Large and deep ulceration with perforation in the small intestine was detected in the posterior gastric wall. The small intestine loop was reached by endoscope through spontaneously developed gastrojejunal fistula.Polytopic biopsies of described ulcerative change were carried out. Histopathologically reepithelialized ulcerous zone was seen in the gastric mucosa. Also,gastrojejunal fistula was visualized after wide opening of hepatogastric and gastrocolic ligament. Jejunal loop 25cm from ligament of Treitz was attached to mesocolon and posterior gastric wall because of ulcer penetration.Postoperative course was uneventful. Per oral intake started on the 4th postoperative day, and the patient was discharged on the 8th postoperative day. In summary,this case indicates that persistent symptoms of peptic ulcer disease associated with nutritional disturbances may be caused by gastrojejunal fistula.