A vascular viscoelasticity evaluation device and method in which, a pulse wave obtained using a cuff is subjected to first derivation, a positive amplitude peak value Vf1 that occurs first and a negative amplitude peak value Vr2 that occurs second out of a plurality of negative amplitude peak values are detected in a state in which an external force substantially the same as or greater than the systolic blood pressure has been exerted on a blood vessel, and a ratio of the positive amplitude peak value Vf1 that occurs first to the negative amplitude peak value Vr2 that occurs second is calculated, and then the vascular viscoelasticity is evaluated on the basis of this calculated ratio.