Hydrogenation of chlorosilane was achieved in acetonitrile using NaBH4, a safe and easy-to-handle reagent. This reaction converted Si-Cl portion(s) in organosilanes into Si-H portion(s) without hydrogenation of cyano, chloro, and aldehyde groups on an alkyl substituent of the Si reagents. In addition, the Si-Cl/Si-H exchange reaction was applicable to dichlorodisilane without Si-Si bond cleavage.