The machine (1) for balancing the wheels of a vehicle comprises: a supporting frame (2) provided with a rotating shaft (20) adapted to support and set a wheel (R) to be balanced in rotation; detection means for detecting the unbalance of the wheel (R); identification means (3) for identifying at least one portion of the wheel (R) for the measurement of characteristic parameters, which comprise: an emitter (30) of laser radiation (31) along an optical emission path (32) lying at least partly on a predefined plane of emission (X-Y); and a detector (34) to receive the laser radiation (31) and arranged along an optical receiving path (35); reflection means (4) adapted to deflect the optical emission path (32) and the optical receiving path (35), the optical emission path (32) being substantially coincident with the optical receiving path (35).