A blood pressure measurement device measures a pulse period of a patient and includes a memory, a threshold calculation section, a rest/unrest condition determination section, and a display unit. The memory stores data of the measured pulse period and data of a pulse period of past measurement of the patient. The threshold calculation section calculates a threshold value range based on the data of the pulse period of the past measurement of the patient. The rest/unrest condition determination section determines whether the patient was under the rest condition or the unrest condition during blood pressure measurement by comparing the measured pulse period with the threshold value range. The display unit displays the blood pressure measured and whether the blood pressure was measured when the patient was in the rest condition or the unrest condition.