A process for the preparation of lithium borohydride by reaction of lithium hydride with boron trifluoride is described, in which lithium hydride is reacted with boron trifluoride in a molar ratio LiH:BF.sub.3 of >4.1:1, the reaction being carried out in an ethereal solvent whose boiling point at normal pressure is at least 50.degree. C., and at temperatures of at least 10.degree. C.