An automatic device for the change of rail (1), particularly for overhead rails, supported in the air comprising a moveable frame (2) linearly displaceable along a support (3) including two roller assemblies (A, B) which may be located in parallel at each side of the rail (4a, 4b) in operating condition, being each of the roller assemblies (A, B) articulated to the support (3), wherein at least one of the roller assemblies is articulated with rotating capacity, so that it is capable to swivel in respect to an articulation point (6), the support (3) being articulated with rotating capacity on the moveable frame (2), for which reason it is capable to rotate in respect to said moveable frame permitting an unlimited number of changes of rail without reducing the operating speed in the change of rail.