An ultrasound diagnostic apparatus includes an acquisition unit acquiring pieces of ultrasound image data at different deflection angles a calculation unit calculating coefficients corresponding to respective positions in ultrasound image data corresponding to a certain deflection angle based on signal or pixel values corresponding to the respective positions in at least one piece of ultrasound image data corresponding to a deflection angle other than the certain deflection angle a multiplication unit multiplying, by the coefficients, signal or pixel values corresponding to the respective positions in the piece of ultrasound image data corresponding to the certain deflection angle, or signal or pixel values corresponding to the respective positions in image data obtained by compounding ultrasound image data corresponding to respective deflection angles including the certain deflection angle and a control unit causing a display unit to display an image based on the signal or pixel values multiplied by the coefficients.