An anti-roll device for a vehicle may include a lower arm disposed at both sides of a sub-frame, a rotation mounter formed at a middle portion of the sub-frame, a spring unit of which the middle portion is rotatably disposed at the rotation mounter, and a push rod connected to both sides of the spring unit and the lower arm, wherein the spring unit includes a plate spring of which both end portions are bent in opposite directions, an engagement portion having an engagement hole in the middle portion thereof is formed, and a bolt hole is formed at both ends thereof, an assistant spring that is disposed at both sides of the engagement portion and an assemble hole is formed in the middle portion corresponding to the engagement hole, and an engagement yoke engaged with the plate spring and the assistant spring and disposed on the rotation mounter.