The mechanical properties of negative Poisson's ratio foams are described under compressive loading both from a numerical and experimental point of view. Different samples of open cell PU (polyurethane) based auxetic foams (i.e. with negative Poisson's ratio) were manufactured following a dedicated manufacturing process, using different compression ratios and temperature profiles. High strain rate and quasi static compressive loading tests were performed in order to benchmark the numerical model. A numerical technique based on loading simulations of statistical assemblies of cells has been adapted to represent the uniaxial compressive behaviour of the auxetic foams. The results can be applied to predict the auxetic foam's behaviour and solving problems related to protection and packaging.