A device for assisting the aligning of a patient support dockable onto an operating table is provided A sensing unit is configured to be arranged on the patient support or the operating table and configured to sense a feature of the patient support and/or of the operating table, said feature lying opposite the sensing unit. The sensing unit configured to sense a position-dependent physical interaction and herefrom to generate a signal that depends on the spatial relative position between the patient support and the operating table. An evaluating unit is configured to receive the signal from the sensing unit and to generate an output that characterizes the relative position between the operating table and the patient support.