The invention relates to a surgical retractor, particularly for the retraction of a separated sternum, with a holding device and two spreader arms, wherein the spreader arms are mounted with one end on the holding device, at a distance from each other that is adjustable in a spreading plane, and at least two retaining elements for retention of bone material, for example of the separated sternum, are arranged on each of the spreader arms. To develop this retractor for sternotomy in such a way as to permit gentler opening of the separated sternum, it is proposed that at least one of the retaining elements is mounted such that its position can be modified in the retraction direction with respect to that end of the spreader arm mounted on the holding device.