A portable ultrasound diagnosis apparatus includes: an ultrasound probe that transmits and receives an ultrasound wave to and from a subject; a processing unit being connected to the ultrasound probe and including a generating unit that generates image data of the subject on the basis of an ultrasound signal received by the ultrasound probe; a display controlling unit that exercises control so as to cause the image data to be displayed by an information terminal being connected to the processing unit and having a display unit; and an identifying unit that performs an identifying process on the basis of identification information of the information terminal. The display controlling unit exercises control so that the information terminal displays a diagnosis image area while varying the size thereof relative to the size of the display unit, in accordance with a result of the identifying process by the identifying unit.