The bracelet is formed of a plurality of links (4, 5) assembled in an articulated manner by means of pins (8). Each pins passes through the interlocking parts of links in which a cylindrical passage is arranged where a pin can slide relatively freely. In order to ensure the position of the pin once the links have been assembled, a locking element (12) is arranged in a cavity (18) made in one of the links so as to partially intersect the passage in which the pin is arranged. This pin includes a groove (22) which an external part (35) of the locking element penetrates when the element is in the closed position. Pressing on the locking element then rotating it through an angle of 90° releases the external part of the pin groove such that the pin is then released. The pin locking device thus allows the links to be assembled in a reversible manner and the length of the bracelet to be varied by adding or removing at least one link.