According to one embodiment, an ultrasound diagnostic apparatus includes a transmitter/receiver and processing circuitry. The transmitter/receiver sequentially transmits a first transmission beam group and a second transmission beam group and receives at least one reception beam for each transmission beam, via an ultrasound probe having a plurality of transducers arranged along an azimuth direction and an elevation direction. The processing circuitry combines a first reception beam based on a first transmission beam included in the first transmission beam group and a second reception beam based on a second transmission beam included in the second transmission beam group. Transmission beams that are adjacent to each other in the azimuth direction or the elevation direction belong to transmission beam groups that are different from each other.
