Duodenal injury following a blunt abdominal trauma is a rare condition. It poses a diagnostic challenge since symptoms are often subtle in the beginning and the trauma may initially remain undisclosed. We present a case of a 16 month-old girl, who was admitted to hospital due to critical illness after a tumble the day before. An explorative laparotomy revealed a perforation of the duodenum. This case demonstrates the importance of thoroughly evaluating anamnesis information and emphasises the need of considering a variety of potential diagnoses when assessing the critically ill child.