Introduction We present a case of a 24-year-old female who presented with the signs and symptoms of acute appendicitis. Case report When computed tomography and ultrasound were not definitive for the diagnosis, the decision was made to perform a laparoscopic appendectomy. The appendix showed no gross signs of inflammation, so intraoperative esophagogastroduodenoscopy was used to examine for a perforated peptic ulcer. When no perforations were found, exploratory laparotomy was performed and revealed purulent fluid in the right colic gutter and a pinhole perforation in the first part of the duodenum. The defect was repaired and the abdominal space was washed thoroughly and closed. The patient recovered well and was discharged from the hospital in good health. Conclusion Valentino's syndrome is an uncommon cause of right lower quadrant pain and symptoms mimicking acute appendicitis.