Abstract: A surgical instrument for fitting a U-shaped osteosynthesis clip having two side bars linked together at the proximal ends by a transverse bar, the transverse bar and the proximal portions forming a proximal region of the clip, the instrument including: at least one recess intended for provisionally receiving the proximal region of the osteosynthesis clip, the distal ends of the two side bars projecting from the instrument; at least blocking means capable of preventing the translation movement of the transverse bar in the proximal and distal directions; at least anti-rotation means preventing the clip from rotating about the transverse bar; and spacing means capable of engaging with the proximal region in order to increase the distance between the distal ends of the two side bars. The invention also relates to a kit including such an instrument and to a clip intended for being received in such an instrument.