The strike mechanism of a watch includes a gong secured by one end thereof to a gong-carrier integral with a plate, a hammer rotatably mounted on the plate for striking the gong at predetermined times, a damping counterspring for keeping the hammer at a distance from the gong in an idle mode, and a drive spring for driving the hammer. The drive spring includes one end secured to the plate and one end that is free to move. The spring is windable so that the free end of the drive spring drives the hammer against the gong in a strike mode to generate an acoustic sound. The strike mechanism further includes a stop member on the path of the hammer drive spring in the direction of the gong for increasing the rotational strike speed following contact of an intermediate part of the drive spring acting against the stop member.