A vehicle slide rail device is provided, which can reduce the possibility of the lock mechanism provided between the upper rail and the lower rail unintentionally lock-releasing when the cushion airbag is inflated.As a solution, the lock-release lever 40 is provided with a lock-release contacting portion 46, which is positioned away from a press portion 65 of the lock operational lever when the lock operational lever is positioned at a lock-allowing position and which receives a force from the press portion for rotating the lock release lever toward the unlocking position when the lock operational lever rotates from the lock-allowing position toward the lock-release position. When the upper rail 30 is deformed downwardly due to pressure by the inflating of a cushion airbag 80, the lock release lever moves downwardly together with a downwardly deforming portion of the upper rail and the lock-release contacting portion moves in a direction to closely approach the press portion of the lock operational lever.