The present invention relates to a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, and to the use of a thus obtained pigment slurry for the preparation of a coating compound for the paper industry or in the paper stock for papermaking. An essential element of the invention is a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, characterized in that the residual water sludges containing the fillers and coating pigments are subjected to mixing and then milling together with fresh pigments or fresh fillers in the form of powders, fresh-pigment containing slurries and/or fresh-filler containing slurries to yield a pigment slurry.