The method for improving cell structure with little or no shrinkage or foam collapse in molded high resilience open celled flexible polyurethane foams prepared by the reaction of an organic polyol having a hydroxyl functionality of at least 2 with an organic polyisocyanate in the presence of a blowing agent. This method comprises incorporating with the reactants three cell modifiers consisting of a polysiloxane-polyoxyalkylene copolymer, a polymethylsiloxane, and a polyether polyol cell modifier containing polyoxyethylene groups in amount of at least about 80 percent by weight of said polyether polyol.