Because of its unique properties, potassium dihydrogen phosphate crystals are widely used for electro-optical applications. Slicing is needed to make potassium dihydrogen phosphate crystal lens with desired shapes. However, reported studies on slicing of potassium dihydrogen phosphate crystal are scarce. This article presents an experimental investigation on slicing of potassium dihydrogen phosphate crystals. Output parameters studied include surface roughness, flatness error, parallelism error, and subsurface damage. Effects of wire sawing input variables (feed rate and diamond grit size) on output parameters are investigated. Comparisons of wire sawing and band sawing are also made.