A timepiece with a movement that includes: a power source; an element for displaying the current time; a chronograph mechanism including a control mobile (60) including at least one control member for activating the start, stop and reset functions of the chronograph. The control mobile (60) further includes a driving member having a toothed sector (84) kinematically connected to the control member. The timepiece further includes a button that can be rotated, the button being rigidly connected by teeth that can be kinematically connected to the toothed sector so that the pivoting of the button activates the start, stop and reset functions of the chronograph.