A surgical stapling instrument (500) including a handle portion (510), a body portion (512), an articulating tool assembly (17) and an articulation mechanism (400) is disclosed. The body portion (512) extends distally from the handle portion (510). The articulation mechanism includes an articulation link (406) for articulating the tool assembly, an articulation knob (402) for rotating an interface member (404), the articulation link (406) having a slit at a proximal end operatively connected to the interface member, wherein rotational motion of the articulation knob is translated into axial motion of the first and second articulation links thereby articulating the articulating tool assembly.