An X-ray diagnostic apparatus according to the present embodiment includes: an X-ray tube which generates X-rays to be irradiated at an object; an X-ray diaphragm which houses an X-ray shielding member forming an irradiation aperture, through which the X-rays pass, along a side surface of the X-ray tube; an X-ray detector which detects X-rays passing through the object; and an image data generation circuitry which generates image data based on the X-rays detected by the X-ray detector.