The invention is directed to an anti-tilt swivel mechanism attaching a seat to a base. The mechanism adapted to control the tilting movement urged on the swivel mechanism when a user shifts weight on the seat. The anti-tilt swivel mechanism comprises a tilt stop mounted on the swivel mechanism to move with the chair and engage the base plate along a front edge. The anti-tilt seat swivel mechanism adapted to engage the base plate when a tilting force is applied to the chair preventing the force from being transmitted as a bending force on the swivel mechanism at the mounting plates or the pivot rod.