A bone resection instrument, comprising means of support and positioning (2) for the correct alignment of the tool (1) with respect to the bone to be cut, a cutting guide (7), connected to the means of support and positioning (2), comprising a support (8) attachable to a bone to be cut. The cutting guide (7) comprises a gauge block (9) having a cutting surface (90) and removably connected to said support (8). The instrument (1) is part of a bone resection kit comprising a plurality of gauge blocks (9), each differing in height (h) from one another.
