An apparatus and a process for controlling tyres wherein the apparatus includes at least one control station which includes: a base; a rotating table mounted on the base so as to be able to rotate around a respective vertical rotation axis; at least one control device operatively active at the rotating table; and a movement device configured for rotating the rotating table around the vertical rotation axis. The rotating table has a substantially horizontal abutment portion configured for receiving and supporting a sidewall of a tyre to be controlled. The abutment portion is movable in the horizontal plane according to two directions with respect to the vertical rotation axis by means of an actuator. A detection device is configured for detecting a shift between the vertical rotation axis and the main axis of the tyre. An electronic management unit operatively connected to the detection device and to the actuator is configured for driving the actuator and moving the abutment portion according to the two directions as a function of the detected shift in order to render such shift less than a pre-established value, so as to center the tyre with respect to the vertical rotation axis before executing the controls.