The present invention relates to a method for recycling of synthetic material containing waste. In the process initially in a first step the synthetic material containing waste is crushed to a particle diameter .ltoreq.100 mm and then admixed as aggregate in a soil material, in particular in a silt containing soil for the earthworks. The portion of the synthetic material containing waste admixed in the second step is preferably 15 percent by volume to 70 percent by volume. The resulting soil material is in many aspects excellently suited for the earthworks and in particular, for the recultivation or the protection of problematic landfill areas.