The device for pivoting an arbour (11) in a timepiece, includes two pivots (12, 12′; 32) each forming one end of the arbour and two bearings for receiving the two pivots. Each of the pivots includes an approximately cylindrical portion (19, 19′; 39) and a convex rounded portion (13. 13′; 33) that extends the approximately cylindrical portion and gradually decreases in the direction of the end. Each of the bearings includes a pivoting structure (25; 35) held in place elastically, which includes an approximately cylindrical passage traversed by said approximately cylindrical portion (19, 19′; 39) of one of the pivots. The pivoting structure also includes a bearing surface against which the end of said pivot will abut. The pivoting device is characterized in that the pivoting structure of each of the bearings includes an aperture (16, 16′; 36; 46) that has a portion of inverted triangular or trapezoidal profile (16, 16′; 38; 46), and in that the convex rounded portion (13, 13′; 33) of one of the two pivots is for abutting against said inclined inner wall so that the arbour (11) is held axially between the inclined walls of the apertures of the two bearings.