A blood rheology measurement device measures a blood rheology of blood flowing through an artery inside of a living body from outside of the living body. The blood rheology measurement device has a sensor that detects a flow rate of blood flowing through the artery and a pulsatile displacement that varies with an elapse of time. The pulsatile displacement corresponds to a displacement of the artery in a diameter direction thereof due to expansion and contraction of the artery resulting from a pulsatile motion of the heart. A calculating section calculates the blood rheology of blood flowing through the artery on the basis of the blood flow rate and the pulsatile displacement detected by the sensor.
