An ultrasound diagnostic apparatus according to an embodiment includes a transmitting unit (101), a beam-forming processing unit (120), and an extracting unit (130). The transmitting unit (101) performs transmission of ultrasonic pulses of different polarities to different transmission positions of a subject for multiple times. The beam-forming processing unit (120) performs, for each of the different polarities, reception beam-forming processing with respect to plural reception signals acquired by transmission of plural ultrasonic pulses of an identical polarity. The extracting unit (130) extracts a non-linear signal by adding up reception signals of the different polarities at an identical reception position, the signals subjected to reception beam forming.