According to one embodiment, an X-ray diagnostic apparatus includes processing circuitry. The processing circuitry generates a plurality of contrast images sequentially based on X-rays after administration of a contrast medium to the object, determines a monitoring region in the plurality of contrast images, monitors change in signal strength of each of pixels included in the monitoring region, and determines whether or not the signal strength of each of the pixels included in the monitoring region satisfies a specified condition. The processing circuitry controls an X-ray generator based on a result of the determination so as to reduce an X-ray dose or turn off irradiation. The processing circuitry generates a parametric image based on a feature amount determined by change in signal strength of each of pixels of a part of the plurality of contrast images sequentially generated before the X-ray generator is controlled based on the result of the determination.
