A radiation imaging apparatus comprising: an image capture unit capturing a radiation image; a first decision unit deciding, as a first region of interest, a region of interest from a region of a first radiation image; a first extraction unit extracting the first region of interest from the first radiation image; a form decision unit deciding a first form from the first region of interest; a first display unit enlarging and displaying the first region of interest; a first search unit searching a region of a second radiation image for a second form similar to the first form; a second decision unit deciding a second region of interest from the second radiation image so as to include the second form; a second extraction unit extracting the second region of interest from the second radiation image; and a second display unit enlarging and displaying the second region of interest.