A method and an apparatus are disclosed for monitoring the state of a roller bearing. The apparatus includes a vibration sensor, configured to detect vibrations which occur during operation of the bearing, and to generate a first signal as a function of the detected vibrations. A diagnosis electronics system is configured to output an item of information about a state of the bearing on the basis of the first signal and at least one limit value stored in the diagnosis electronics system. A sound emission sensor is provided, configured to pick up noises, produced in the event of plastic deformation of the bearing at least in regions. A second signal is then transmitted to the diagnosis electronics system, taking into account the picked-up noises.