PCX is an computer data format that stores raster image information originally created by ZSoft and made popular by the program PC Paint Brush. It is one of the earliest formats for storing image data which started in the early 1980's. PCX allows from 1 to 24 bit color depth and with or without a color palette.

This format uses mandatory RLE compression which makes it a poor choice for photographic data, but much better than uncompressed formats such as BMP for graphic images like screenshots.

The original specifications of PCX have undergone several modifications from it's original structure in order to stay up to date with the multimedia world. However, even with its modifications it has slowly become out of use because more advanced formats like PNG have replaced it.

PCX has also spawned other file extensions like *.DCX (used to store multiple PCX files), *.PCJ (A PCX image with its palette stored in a P13 file), *.P13 the palette for PCJ files).