The invention relates to a bracelet clasp including a securing member provided with means for adjusting the useful length of the bracelet, these adjustment means including: a base plate secured and pivotally hinged to the second end of the second strip, the first strand passing between the base plate and the second strip and being held by holding means, second means for locking the base plate in a closed position on the second strip. According to the invention, the second locking means include a push-piece arranged to be moved between a first rest position wherein the base plate is locked in a closed position on the second strip, and a second pushed-in position in which the base plate is released from the second strip.