BACKGROUND: Sacroiliac joint (SIJ) remodeling in pediatric patients following trauma is a rare phenomenon with limited documentation in medical literature. This case report presents a unique instance of post-traumatic SIJ remodeling in an 11-year-old girl following a motorbike accident, highlighting novel imaging findings and successful outcomes achieved through a multidisciplinary approach. CASE PRESENTATION: The patient presented ten days post-injury with severe right hemi-pelvic pain and limited leg mobility. Initial imaging revealed dislocation of the right SIJ, along with superior and posterior hemi-pelvic displacement and pubic symphysis separation. Initial attempts at closed reduction were unsuccessful, necessitating surgical intervention with percutaneous SIJ screw placement and external fixation. Despite incomplete reduction, multidisciplinary rehabilitation was initiated. At the three-month follow-up, the patient was walking pain-free, with CT scans showing significant SIJ remodeling as the joint adapted to the sacral surface. The SIJ screw was removed at six months, with the patient returning to full function, equal limb lengths, and no residual deficits. CONCLUSIONS: This case underscores the distinct anatomical and physiological responses of the pediatric SIJ to trauma. Early diagnosis, multidisciplinary management, and careful consideration of growth factors are crucial for favorable outcomes in pediatric post-traumatic SIJ injuries. This report highlights the potential for significant joint remodeling and emphasizes the importance of tailored rehabilitation in pediatric cases.