A microelectromechanical mirror device (1) is provided with: a fixed structure (4) defining a cavity (3); a tiltable structure (2) carrying a reflecting surface (2'), elastically suspended above the cavity and having a main extension in a horizontal plane (xy); a first pair of driving arms (12a, 12b), carrying respective piezoelectric material regions (13) designed to be biased to cause a rotation of the tiltable structure around at least one first rotation axis (X) parallel to a first horizontal axis (x) of the horizontal plane, elastically coupled to the tiltable structure; and elastic suspension elements (6a, 6b), which couple the tiltable structure to the fixed structure at the first rotation axis, stiff with respect to movements out of the horizontal plane and yielding with respect to torsion around the first rotation axis, extending between the tiltable structure and the fixed structure. The elastic suspension elements comprise a first and a second elastic suspension element, wherein a first torsional stiffness of the first elastic suspension element is different from a second torsional stiffness of the second elastic suspension element.