An ultrasound imaging apparatus capable of easily displaying a three-dimensional image included in a region of interest (ROI) is provided. A display controller 9 causes a display 10 to display a tomographic image, and further causes the display 10 to display a first marker indicating a three-dimensional scan range and a second marker indicating a range to generate three-dimensional image data (a range subjected to rendering) so as to be superimposed on a tomographic image. The second marker is rotatable on the tomographic image in accordance with an instruction by an operator. A transceiver 3 causes an ultrasound probe 2 to scan the three-dimensional scan range specified based on the first marker. An image processor 7 executes rendering on, of data acquired in the scan, data included in the range specified based on the second marker, thereby generating three-dimensional image data.
