Abstract: A device for fastening a wristlet to a watch case includes an end body of the wristlet, at least one movable fastening element comprising a pivot part movable between an engagement position in which the pivot part is engaged with the case, and a retracted position where the pivot part is disengaged from the case, a lever movably mounted in rotation on the end body, at least one movable cam engaged with the lever to switch the movable fastening element from the engagement position to the retracted position during a rotation of the lever, where the device comprises at least one static cam fixedly mounted on the end body facing the movable cam, to impose an axial movement on the movable cam during its rotation, and the movable cam is directly formed on the movable fastening element, and arranged between the lever and the static cam.