Abstract: There is disclosed a method for determining the position of positioning means (12, 13, 14) with respect to a known reference, intended to be implemented on a machine-tool (1) for machining printed circuit boards, of the type including in particular a workpiece carrier (3) and at least a motorised spindle (8) carrying a tool (6). Said machine-tool (1) further includes a control unit including in particular programmable electronic means allowing the method according to the invention to be implemented automatically, by moving said motorised spindle (8) and detecting electromagnetic or electric interactions between said tool (6) and said positioning means (12, 13, 14).