An angular adjustment mechanism for a surgical instrument is described. The mechanism comprises an adjustment member (102) configured for rotation about a longitudinal axis (122), the adjustment member comprising a plurality of pairs of facets (134) arranged about the longitudinal axis. Each of the plurality of pairs of facets defines a respective angled axis (148B,148C) at an angle (150B,150C) relative to the longitudinal axis. A pivoting member (104) is arranged to pivot about a pivot axis perpendicular to the longitudinal axis and comprises a recess (128) for receiving the adjustment member and engaging one pair of the plurality of pairs of facets. This provides an angular adjustment mechanism in which facets on the outside of the adjustment member engage corresponding surfaces in a recess on a pivoting member. The use of facets provides a secure connection while allowing a greater degree of angular adjustment and providing a further benefit of simple operation.
