We report a case of acute presentation of a solid pseudopapillary tumor of the pancreas in a young boy who had suffered a blunt abdominal trauma. Urgently performed CT examination and repeated ultrasound revealed a subhepatic mass, which gradually increased in size, but the imaging features were not specific enough to permit a precise diagnosis. Because signs of peritoneal irritation and increased circulatory instability gradually developed within the hours of observation, the decision was made to perform an urgent exploratory laparotomy. The exploration revealed a hematoperitoneum and a large hematoma-like subhepatic bleeding mass. Further exploration showed that this mass was a tumor arising from the head of the pancreas, which had ruptured on the surface. A curative pancreatoduodenectomy was performed. Pathohistological examination of the resected specimen revealed a solid pseudopapillary tumor of the pancreas, an extremely rare tumor predominantly occurring in adolescent girls and in young adult women. It has a favorable prognosis if resected radically. The boy in our report is feeling well 36 months after the operation.