A vehicle seat slide device includes: a moveable rail capable of sliding along the fixed rail a main roller provided on each of opposite end portions of the moveable rail in a longitudinal direction and capable of rolling on a bottom wall of the fixed rail a bracket turnably supported on the moveable rail via a pin a biasing unit attached to the moveable rail and constantly applying a rotational biasing force to the bracket about the pin by pushing one end portion of the bracket and a sub roller arranged on another end portion of the bracket and capable of rolling with the sub roller constantly in sure contact with the top wall of the fixed rail in response to the rotational biasing force.
