This positioning system (100) for a bone resecting instrumentation comprising a resection driver (2), comprises at least one of a gyroscopic sensor (8) integral in motion with the resection driver (2) and adapted to sense a deviation angle (θ) with respect to a reference direction (X), and at least one positioning marker (12; 140) marking a fixed position on the reference direction (X), and a depth sensor (10; 18) integral in motion with the resection driver (2), for detecting a resection depth (d) based on the relative longitudinal positions of the positioning marker (12; 140) and the depth sensor (10).The invention also concerns a positioning kit including such a positioning system and a separate electronic device.