In children with open physis, avulsion fracture of the tibia eminence, as an anterior cruciate ligament (ACL) injury, is more commonly observed than an ACL rupture. Pure cartilaginous avulsions of the ACL tibia insertion seldom occurs. In such case, cartilaginous lesion is frequently overlooked or misdiagnosed on plain radiograph and may result in a less favorable treatment outcome. We report two cases of cartilaginous tibia eminence fractures of the children that were initially overlooked from plain radiographs, and then diagnosed by magnetic resonance imaging, which was ultimately treated by arthroscopyassisted headless compression screw fixation.