Peptic ulcer perforation is the cause of aproximately 5% of acute abdomen cases. Closed perforation incidance in these patients, is quite rare and there is no certain reports in the literature. It? is difficult to diagnose unless peritonitis occurence. The management of closed perforation treatment can be made by operative or non operative. We frequently use the metilen blue which have been widely used on gastrointestinal tract surgery for localization of perforation or anastomosis leakage test in our centre, too. We present a 54 year-old man patient with no findings of acute abdomen on applying time and he performed acute abdomen on following second day. So emergency laparotomi performed and bilios, with fibin, dirty content were seen during the operation and perforation localizated with administration of metilen blue from nasogastric tube.