An ultrasound diagnostic apparatus according to an embodiment includes a memory unit and a converting unit. The memory unit stores therein conversion information, for each ultrasonic probe, converting a coordinate of an attachment position of a position sensor attached to an ultrasonic probe into a coordinate of a predefined position on a surface for transmitting and receiving ultrasonic waves on the ultrasonic probe. When the ultrasonic probe is replaced with another ultrasonic probe, the converting unit acquires conversion information corresponding to the replacing ultrasonic probe and uses the conversion information thus acquired to convert the coordinate of the attachment position of the position sensor attached to the replacing ultrasonic probe into the coordinate of the predefined position.
