An image processing system according to an embodiment includes a stereoscopic display device, a receiving unit, and a display controller. The stereoscopic display device displays a stereoscopic image that is capable of being viewed stereoscopically using a parallax image group as a plurality of parallax images generated by performing rendering processing on volume data as three-dimensional medical image data. The receiving unit receives a region of interest in the stereoscopic image. The display controller causes the stereoscopic display device to display the parallax image group that has been generated by performing the rendering processing on the volume data based on a plurality of viewpoint positions of which sight line directions intersect with one another at a position of the volume data that corresponds to the region of interest received by the receiving unit.