An X-ray diagnosis apparatus according to an embodiment includes an X-ray tube, judging circuitry, and grid controlling circuitry. The X-ray tube is configured to radiate X-rays. The judging circuitry is configured to judge whether a voltage should be applied to a grid of the X-ray tube or not, in accordance with a radiation condition. The grid controlling circuitry is configured to apply the voltage to the grid, if the judging circuitry has determined that the voltage should be applied.