An ultrasound diagnostic apparatus according to an embodiment includes processing circuitry. The processing circuitry causes an ultrasound probe to execute first ultrasound scanning to acquire blood flow information within a first scanning area and causes the ultrasound probe to execute second ultrasound scanning to acquire tissue shape information within a second scanning area. The processing circuitry receives an instruction for changing a flow-velocity value to be displayed in display of the blood flow information. When, because of a change of the flow-velocity value according to the instruction, a time for transmitting/receiving ultrasound per scanning line in the first ultrasound scanning exceeds a transmitting/receiving time before the change, the processing circuitry assigns a time corresponding to the excess to at least one of the first ultrasound scanning and the second ultrasound scanning.
