A method of clarifying oily waste water comprising adding to the waste water an effective clarifying amount of one or more demulsifiers selected from the group consisting of dendritic polyamines, dendritic polyamidoamines and hyperbranched polyethyleneimines and the reaction products thereof with gluconolactone, alkylene oxides, salts of 3-chloro-2-hydroxypropanesulfonic acid, alkyl halides, benzyl halides and dialkyl sulfates.