Studying the relation between microstructural phenomena and the macroscopic behaviour will provide a way to design the microstructure of a material such that specific requirements on the resulting macroscopic mechanical behaviour can be fulfilled. One way to obtain a quantitative relation between the separate scales is to use homogenisation methods. A numerical homogenisation method has been developed to model the mechanical behaviour of heterogeneous elastoviscoplastic solids at finite strains, The thus obtained constitutive equation enables the modelling of complex macrostructures, while taking into account the influence of the microstructure. The method has been validated by comparing results of homogenised simulations with reference solutions. For this purpose, a specimen with a periodic microstructure and an irregular microstructure has been considered. The continuous matrix material is assumed to be polycarbonate, whereas the heterogeneities are taken to be rubber particles and voids.