A method for feeding a twisted metal cable (3) braided into a plurality of braids or a flat wire from a support or spool (2) to a winder or winding machine (5), said feed comprising unwinding the cable or wire (3) from the spool (2), measuring at least one property of the cable or wire from among its tension, velocity and quantity, possible adjustment of said property and feeding the cable or wire to said machine with the aforesaid said property being held constant. The cable or wire is unwound in a controlled way in a direction at right angles to the axis (W) of the spool (2) directly from such spool (2) or through a return member (10) which receives the cable or wire from the spool (2) from which it is unwound in an uncontrolled way, such controlled unwinding preventing the cable (3) changing the structure of its braids through loosening or stretching and that said wire undergoes torsion before its property is measured. The system implementing such method is also claimed.