[Object] To present a three-dimensional image in a more favorable mode, regardless of differences in display conditions. [Solution] A medical stereoscopic observation device including: an acquisition section that acquires input image data a parallax control section that controls, for each of a plurality of different display regions, a parallax value in accordance with display size of the display region and an image generation section that generates, for each display region, a parallax image corresponding to each of a plurality of viewpoints for display in the display region, on a basis of the acquired input image data and the parallax value corresponding to the display region.