BACKGROUND: Long-term changes of gastric mucosa following surgery for morbid obesity have never been studied, to the best of our knowledge. As 31 patients in our series presented with various gastrointestinal complaints following surgery, we used this opportunity to study mucosal changes. METHODS: Thirty-seven gastroscopies were performed on 31 patients, 20 patients following Vertical Banded Gastroplasty (VBG) and 11 patients following Silastic Ring Vertical Gastroplasty (SRVG) with various gastrointestinal complaints. Macroscopic appearance of the gastric mucosa was examined and biopsies taken from the proximal gastric pouch, the transitional zone and distal stomach. RESULTS: In most patients, macroscopic appearance of the proximal and distal pouches was normal. Pathological findings were mainly located in the transitional zone and were found mainly in the VBG group. CONCLUSIONS: This study indicates that damage to the gastric mucosa is related to the surgical technique, and mainly to the strip of mesh used in the VBG patients. Since hyperplasia and metaplasia were among the microscopic findings, a question is raised about the possibility of malignant transformation. We suggest that routine post-operative gastroscopies be considered, especially following VBG.