Perforated duodenal ulcer (PDU) is exceedingly uncommon in children. In a child with acute abdomen and pneumoperitoneum, an appendiceal etiology is more often suspected as a likely cause. Failure or delay to diagnose a PDU can result in significant morbidity and even mortality. We report a case of acute abdomen in a girl with PDU with a successful outcome. A 12-year-old school girl presented to emergency room (ER) with acute generalized abdominal pain for 2 days. Clinical examination revealed florid peritonitis, and abdominal radiographs showed free peritoneal air. At emergency laparotomy, PDU was noted with general peritoneal contamination. Omental patch repair and continued supportive care resulted in gradual improvement. PDU is an uncommon cause of peritonitis in children and poses significant challenges in management. Strong suspicion and prompt appropriate intervention is necessary to avoid untoward outcomes.