Epiphysiolysis of the dens axis at the infant age is a rare injury, which must be surely clarified at car accidents with frontal application of force at medium high speed. We report of a small patient sitting in a child seat, who suffered a epiphysiolysis of the dens axis, which was initially not diagnosed, due to a abrupt deceleration in the context of a car accident. The epiphysiolysis of the dens axis could be secured with the aid of conventional radiography, MRT and CT. The delayed conservative treatment due to the anamnesis was then complicationless.