You can use a projector without a projection screen, though having a screen in your home theater will enhance the viewing experience. Using a projector without a projection screen can impact the quality of the image you're viewing. If you don't have a projection screen, you can use a simple white wall as a viewing surface. Just keep in mind that the wall won't reflect light as well as a screen would, nor will you find a wall that's as smooth as a projection screen. Additionally, projection screens have a special coating. This coating improves the screen's reflective properties. All in all, while an image you project onto a wall won't be nearly as bright as it would on a projection screen, you can still enjoy your projector this way.