An orthopaedic stapler (1) comprising orthopaedic pliers (3) and an orthopaedic staple (2) integrally formed at the distal ends of the pliers (3). The orthopaedic staple (2) comprises a beam portion (4) and two insertion brackets (5) at the two opposite ends (6) of the beam portion (4) and substantially transverse with respect to the beam portion (4). The orthopaedic pliers (3) comprise two lever arms (12) integrally connected to the orthopaedic staple (2) by means of connection portions (15) at the two opposite ends (6) of the beam portion (4). The connection portions (15) are breakable along breakage sections (24). The lever arms (12) comprise at least one first projecting element (19), at least one second projecting element (20), the first projecting element (19) on one lever arm (12) being directed towards the second projecting element (20) on the other lever arm (12). The first projecting element (19) and the second projecting element (20) are provided with a reciprocal engaging mechanism (21).