Abstract: Lacing system for ski boots adapted to pull tight the boot flaps around a skier's foot by means of fastener devices comprising each a first over-center hooked latching lever arranged on one of two flaps of the boot uppers, and a connecting link secured to the other of the two flaps of the boot uppers and insertable into adjustment notches provided on the first lever. A second over-center lever has hinge means for hingedly securing it on the above one flap and having pivot means for pivotally supporting thereon the first lever. The pivot means are offset with respect to the hinge means thereby to act through the second lever on the first lever via the pivot means.