An ultrasound diagnostic apparatus according to an embodiment includes a transmitter/receiver, an adder/subtractor and an image generating unit. The transmitter/receiver performs a first set of ultrasound transmission/reception and a second set of ultrasound transmission/reception, on a same scanning line of an imaging region of a subject administered with a contrast agent, for a plurality of sets, to output reflected wave data for the plurality of the sets, the first set of the ultrasound transmission/reception performing amplitude-modulated or amplitude- and phase-modulated ultrasound transmission transmitted a plurality of times and receiving reflected waves, and the second set of the ultrasound transmission/reception being transmission/reception whose phase modulation being different from phase modulation of the first set of the ultrasound transmission/reception. The adder/subtractor adds or subtracts the reflected wave data for the plurality of the sets. The image generating unit generates contrast image data based on the data output from the adder/subtractor.
