A blood-pressure measurement apparatus according to an embodiment comprises a measurer and a blood-pressure acquirer. The measurer is configured to measure a pulse of a subject based on a received-light signal scattered in a body of the subject when a light signal in a predetermined frequency band is irradiated. The blood-pressure acquirer is configured to acquire a diastolic blood pressure based on a first value and a second value, the first value corresponding to a blood flow of the subject in a first time period in a time period from a first reference time at which a value obtained by first-order differentiation of the pulse with respect to a time becomes the maximum to a second reference time at which a next pulse rises, the second value corresponding to a vascular resistance of the subject.
