An ultrasound diagnostic apparatus according to an embodiment includes a detector, a determination unit, a retention controller, and a display controller. The detector is configured to detect a peak flow velocity of blood flow velocities acquired from Doppler waveforms collected in a time-serial manner or a peak value of average flow velocities of the blood flow velocities as a representative flow velocity for each predefined period. The determination unit is configured to determine a maximum value in a predefined polarity of a plurality of representative flow velocities. The retention controller is configured to control a memory unit to retain maximum waveform information that is Doppler waveform information of Doppler waveforms collected for a period in which the maximum value was detected. The display controller is configured to control a display unit to display the maximum waveform information with Doppler waveform information having been collected by a present time point.