Abstract: An apparatus for measuring on the site of an accident the three-dimensional deformation of a damaged vehicle comprises a reference frame and a distance measuring device. The reference frame comprises a first straight frame portion installed in front of the vehicle parallel to the transversal axis thereof, a second elongated straight frame portion installed on the side of the vehicle parallel to this vehicle's longitudinal axis, and a third elongated straight frame portion installed at the rear of the vehicle parallel to the transversal axis. When the deformation is situated in front of the damaged vehicle, the first frame portion defines a first axis of a three-dimensional coordinate system, the second axis of this coordinate system being located in a vertical plane in which the first elongated frame portion is lying.