According to one embodiment, an X-ray diagnostic apparatus includes processing circuitry. The processing circuitry is configured to control an X-ray tube to perform an X-ray irradiation, that is performed prior to an X-ray imaging performed on an object, based on an imaging condition where at least one of an X-ray irradiation range and dose is smaller than an imaging condition of the X-ray imaging. Further, the processing circuitry is configured to evaluate a positional relationship between the X-ray tube and an X-ray detector based on a detection result of an X-ray irradiated in the prior X-ray irradiation by the X-ray detector.