An adjustment mechanism for a casement window assembly includes a rotatable adjuster and a moveable mounting member adapted to be operably connected to a hinge mechanism of the window assembly. The adjuster is non-eccentric, having a cam portion and a non-eccentric rotational axis. The mounting member includes a swivel mount adapted to be pivotably connected to one of the arms of the hinge mechanism and an engagement member connected to the swivel mount. The engagement member includes a plurality of engagement surfaces. Rotation of the adjuster causes the cam portion to engage one or more of the engagement surfaces, thereby exerting a force on the engagement surfaces to move the moveable member, adjusting the position of the swivel mount.