A fluid dispenser valve having a valve body (10) containing a metering chamber (20), and a valve member (30) that is slidable in the valve body (10) between a rest position and a dispensing position so as to dispense the contents of the metering chamber (20) selectively. The valve member (30) is urged resiliently towards its rest position by a spring (8) that co-operates firstly with the valve body (10) and secondly with a radial collar (320) of the valve member (30), the radial collar (320) being of a shape that is polygonal, the vertices (325) of the polygon being substantially rounded.