A vehicle steering device includes: a target-steered-angle setting unit configured to set a left target steered angle that is a target value of the steered angle of a left steered wheel and a right target steered angle that is a target value of the steered angle of a right steered wheel; left motor controllers configured to control a left steering motor based on a left-steered-angle deviation that is a difference between the left steered angle and the left target steered angle; right motor controllers configured to control a right steering motor based on a right-steered-angle deviation that is a difference between the right steered angle and the right target steered angle; and an abnormality determination unit configured to determine that an abnormality has occurred when an absolute value of difference between the left-steered-angle deviation and the right-steered-angle deviation is equal to or larger than a first threshold.