A method of producing a hydrophilic polyurethane foam structure containing a silver salt, chosen from the group of silver sulphate, silver citrate, silver acetate, silver carbonate, silver lactate and silver phosphate, or a mixture of these salts includes the steps of (a) providing a water phase containing a surfactant, and at least one silver salt, wherein the at least one silver salt is dispersed in the water phase (b) providing a isocyanate-terminated polyether having functionality of more than (2) (c) mixing the water phase and the isocyanate-terminated polyether, immediately transferring the resulting mixture to a mould whereby a foam structure is obtained and (d) drying the foam structure until it has a moisture content of at most 10% (wt). The hydrophilic polyurethane foam structure produced by the method and a wound dressing containing the foam structure are also described.