An ultrasonic diagnostic apparatus according to the present embodiment includes an ultrasonic probe, image generation circuitry, acquisition circuitry, calculation circuitry, guide image generation circuitry, and control circuitry. The ultrasonic probe transmits ultrasonic waves, and receives reflected waves. The image generation circuitry generates cross-section image data based on the reflected waves. The acquisition circuitry acquires, from volume data corresponding to three-dimensional region containing a blood vessel inside the subject, cross-section position information corresponding to the cross-section image data. The calculation circuitry calculates collection position information in the volume data based on a running direction of a blood vessel contained in the volume data, the collection position information corresponding to a position from which blood flow velocity information is collected. The guide image generation circuitry generates guide image data based on the cross-section position information and the collection position information. The control circuitry causes the guide image data to be displayed.