A method for producing monohydroxy-functionalized dialkylphosphinic acids, esters, and salts, characterized in that a) a phosphinic acid source (I) is reacted with olefins (IV) in the presence of a catalyst A to obtain an alkylphosphonous acid, the salt or ester (II) thereof, b) the obtained alkylphosphonous acid, the salt or ester (II) thereof is reacted with alkylene oxides of formula (V) in the presence of a catalyst B to obtain a monofunctionalized dialkylphosphinic acid derivative (III), catalyst A represents transition metals and/or transition metal compounds and/or catalyst systems composed of a transition metal and/or a transition metal compound and at least one ligand, and catalyst B is a Lewis acid.