The most common cause of acute abdomen in children is appendicitis. However, in cases when the appendix is observed normally during surgery, other surgical causes should be considered. Rarely, in the differential diagnosis of right lower quadrant (RLQ) pain, gastric or duodenal ulcer perforation, defined as Valentino Syndrome, should be considered and evaluated for possible pathology. In this case report, we aimed to discuss a case of unusual gastric perforation that presented with symptoms and signs suggestive of appendicitis. Free air was not identified on plain abdominal x-ray, and also no specific finding was found on ultrasonography. The appendix was normal during surgery. There was plenty of serous fluid in the right lower quadrant. When fibrin was observed in upper quadrants, the incision was expanded and it turned out to be a gastric perforation and was repaired. In cases with peritonitis findings in the examination of the abdomen, even though the appendix is normal, it is very important to evaluate all intraabdominal organs in terms of other diagnoses.