Abstract: Improved process for producing a complex elastic molded structure of the sandwich type, consisting of a core of polyurethane foam (10) surrounded by a skin, of which at least a part is reinforced with a reinforcing textile sheet (5, 6) impregnated with a thermosetting resin adhering to said foam, which process consists in:firstly depositing on one of the faces (4) of a mold intended to be closed by a cover (2) an assembly comprising a stiffening element (12) and a semirigid reinforcing textile sheet (6), preimpregnated with a solventless, non-tacky epoxy resin,then closing the cover (2) of the mold (1) so as to define, together with said assembly, a volume corresponding to the volume of the core which is to be formed;then injecting into the volume thus defined the reactional mixture forming the polyurethane foam,and finally allowing the product to cool and opening the mold (1) to withdraw the resulting elastic complex molded structure.