The disclosure relates to a method for controlling a transmission power for a radio connection from at least one interior antenna of a motor vehicle to at least one radio device outside of the vehicle. At least one seat occupancy sensor of the motor vehicle signals seat occupancy of an associated vehicle seat by means of an associated occupancy signal. The transmission power at the at least one interior antenna is controlled in accordance with the occupancy signal. The disclosure further relates to a control device and to a motor vehicle having such a control device.