Fractures of the proximal tibial epiphysis are rare, representing less than 3% of all epiphyseal and 1% of all physeal injuries in adolescents. Bilateral injuries are extremely rare. The specific anatomical and histological features of the proximal tibial epiphysis make it vulnerable to a specific fracture pattern that occurs when the tensile force of the quadriceps is greater than the fibrocartilaginous tissue underlying the tibial tuberosity. We report the first case to our knowledge of a 12-year-old boy who sustained simultaneous bilateral tibial avulsion fractures on the background of a previous conservatively managed unilateral tibial tuberosity avulsion fracture. We report this case for its uniqueness and as an educational review of the anatomy, the mechanism of injury, and the development of classifying these fractures and discussion of the stages of the growing physis that determine the treatment approach.