<prompt> Most common location of peptic ulcer is -1st part of duodenumLesser curvature of stomacGastric antrumAt gastro-esophagal junction  <response>: Ans. is a i.e., 1st part of duodenum Peptic ulcers are located in the following sites, in order of decreasing frequency Robbins 7e1. Duodenum, 1st portion2. Stomach, usually antrum3. At the gastro - esophageal junction, in the setting of gastroesophageal reflux or Barretts esophagus4. Within the margins of a gastrojejunostomy5. In the duodenum, stomach or jejunum of patients with Zollinger-Ellison Syndrome6. Within or adjacent to Meckels diverticulum that contains ectopic gastric mucosa 