The paper describes the case of a 14-year-old male presenting to the Emergency Unit with continuous pain in the right iliac fossa and a slight limp. Initially suspected to be acute appendicitis, the clinical picture was reconsidered due to negative inflammatory markers and persistent pain during active hip flexion. Detailed clinical history revealed a sport-related injury (sprinting phase) occurring seven days prior. A pelvic X-ray confirmed a 2 cm bone avulsion of his right anterior inferior iliac spine (AIIS). The discussion emphasises that the injury, common in adolescent athletes due to the vulnerability of growth plates, requires a conservative approach based on functional rest. The case highlights the importance of accurate differential diagnosis between abdominal pathologies and musculoskeletal injuries in paediatric patients