According to one embodiment, a gesture detection supporting system for an X-ray diagnosis includes memory circuitry, a sensor, processing circuitry and an attaching instrument. The memory circuitry stores an operation content of an X-ray diagnostic apparatus. The operation content is related to a gesture by a user. The sensor senses a gesture. The processing circuitry detects the gesture, based on an output from the sensor; acquire the operation content of the X-ray diagnostic apparatus, from the memory circuitry, based on a detection result of the gesture; and output operation information to the X-ray diagnostic apparatus, based on the operation content. The attaching instrument attaches the sensor to a ceiling of an examination room, an arm for driving an X-ray tube and an X-ray detector, an intravenous drip stand, an injector of a contrast agent, an X-ray protective board and/or a display for displaying an X-ray image.