Abstract: The invention relates to a process for preparing polyether alcohols by reacting one or more alkylene oxides having one or more H-functional starting substances in a continuous reactor that comprises flow channels, at a temperature of 180° C. to 250° C. and a pressure of 60 to 150 bar in the presence of a basic, metal-containing catalyst, wherein the concentration of the catalyst, based on the total amount of reaction mixture of alkylene oxide, H-functional starting substance and catalyst, is no more than 50 ppm by weight, and the residence time of the reaction mixture in the reactor is 15 to 120 minutes.