The feasibility of utilising solid residues of the municipal wastes incineration such as grate (bottom) ash and electrofilter and sleeve filter fly ash, in combination with a porcelain stoneware body, in the preparation of tiles has been investigated. While the chemical, mineralogical, thermal and rheological characterisation of the waste raw materials carries out some problems arising by using fly ash, these seem to be overcome with the bottom ash. The introduction of up to 20 wt% of this powder into the ceramic body does not substantially change the mineralogical and thermal behaviour of the product.