Abstract: This wristlet clasp with unfolding buckle has a central portion made of two curved plates of which the relative position is adjustable and which can be secured by means of screws, the arms hingedly connected to the ends of this central portion being provided with side webs adapted to be secured by snap action to the widest element of the central portion of the clasp. The ends of the two arms to which the wristlet sections are attached and the gap possibly left between these ends in the closed clasp position are concealed by a cover plate adapted to be decorated.