Polyurethane foam and pneumatic tire comprising the same

A polyurethane foam which is obtained by a reaction between a diol component and a diisocyanate component, with the diol component being a mixture of a polyether-based diol and a polyester-based diol, and a pneumatic tire to which the polyurethane foam is applied are provided. When a soft polyurethane foam is produced using a mixture of a polyether-based diol and a polyester-based diol as the diol component, and by varying the content of the expanding agent during the production process, and when the polyurethane foam is disposed in the cavity of a pneumatic tire, the polyurethane foam thus produced has an effect of reducing the resonance noise generated in the cavity of the tire and improving durability of the tire.