According to embodiment, an X-ray diagnostic apparatus includes a frame holding an X-ray tube and detector such that an axis connecting a X-ray focus and center of the detector rotates around an isocenter, display displaying a first image, operation circuitry inputting a position of a target region on the image, target position calculation circuitry calculating a position of the region on a second image based on an angle between the axes concerning the first and second images, a first distance from the isocenter to a top plate, and second distance from the target position to the plate, and top plate movement amount calculation circuitry calculating a top plate movement amount to display the region at a same position as the target position on the second image based on the calculated position, target position, angle, and first distance.
