Process for preparing higher hydridosilanes of the general formula H—(SiH2)n—H where n≧2, in which—one or more lower hydridosilanes—hydrogen, and—one or more transition metal compounds comprising elements of transition group VIII of the Periodic Table and the lanthanides are reacted at a pressure of more than 5 bar absolute, subsequently depressurized and the higher hydridosilanes are separated off from the reaction mixture obtained.