A synchronous motor control device for an electric vehicle is provided which is able to reduce torque ripple through simple calculation and is excellent in practicability. In a synchronous motor control device which controls a traction synchronous motor, torque ripple compensation unit is provided which adds, to a motor drive current, a sine-wave correction current whose phase is opposite to that of torque ripple which is generated in the motor and has a frequency which is six times that of a rotation speed of the motor. Specifically, in the case of a configuration including a vector control type basic controller, the torque ripple compensation unit outputs a correction current command iq_c, and a value iq_ref obtained by adding the correction current command iq_c to a q-axis current command is used for control.