This invention relates to a process for the production of long-chain polyether polyols without working up, in which oligomeric, alkoxylated starter compounds having molecular weights of 200 to 1000 are first obtained by catalysis with perfluoroalkylsulfonates of the metals of group III A of the periodic system of elements (in accordance with the IUPAC convention of 1970) from low molecular weight starters by reaction with alkylene oxides at reaction temperatures of 80 to 200.degree. C. and catalyst concentrations of 5 to 200 ppm, which oligomeric, alkoxylated starter compounds are then converted without working up and removal of the catalyst by means of highly active DMC catalysts at a catalyst concentration of 30 ppm or below, relative to the quantity of polyether polyol to be produced, by reaction with alkylene oxides into higher molecular weight, long-chain polyether polyols.