An X-ray diagnostic apparatus according to an embodiment includes an X-ray tube, a detector, an acquisition circuitry, and imaging control circuitry. The acquisition circuitry creates photon count data indicating the number of photons of the X-rays incident on the detector, for each of a plurality of energy bins for identifying a plurality of target substances, based on the detection signal output by the detector. The imaging control circuitry determines an imaging plan including at least one of a setting condition that is a condition concerning setting of a plurality of energy bins used when the acquisition circuitry creates photon count data in main imaging, and an X-ray radiation condition that is a condition concerning X-rays emitted by the X-ray tube in main imaging, based on the photon count data created by the acquisition circuitry or image data of the subject.
