Apparatus (1) for checking tyres, comprising : a support frame (2); a flange (3); and an acquisition system (4) of three-dimensional images of a surface of a tyre, the acquisition system being mounted on the support frame and comprising : a matrix camera (5), a linear laser source (7), and a reflecting surface (12) which intersects the propagation axis (9) of the linear laser beam and the optical axis (6) of the matrix camera (5), wherein a first angle (50) formed between a first section (14) and a second section (31) of the optical axis (6) mutually symmetrical with respect to a normal to the reflecting surface in the respective point of incidence to the reflecting surface, is obtuse, and wherein a second angle (51) formed between a first section (16) and a second section (32) of the propagation axis (9) mutually symmetrical with respect to a normal to the reflecting surface in the respective point of incidence to the reflecting surface, is obtuse.