The present invention relates to a method and an apparatus for applying noise reducing elements to tyres for vehicle wheels. Noise reducing elements (12), all equal to each other, are fed in succession on a conveyor (20) according to a predetermined path and are oriented on the predetermined path all in the same way. Tyres (2) of different sizes (C, P) are fed in succession on a conveyor (20) up to an application station (34). In the application station (34), the noise reducing elements (12) are picked up from the conveyor (20) and applied to radially inner surfaces of the tyres (2). The application comprises: arranging the noise reducing elements (12) with the larger dimension (L) directed in a circumferential direction or arranging the noise reducing elements (12) with the larger dimension (L) directed in an axial direction as a function of the sizes (C, P) of the tyre (2) in which they are applied.