Co-firing coal with waste wood is the most promising option to contribute to the thermal recycling of solid wastes. However, the utilisation of this fuel mixture in the existing combustion systems may have serious effects on fuel preparation, combustion behaviour, gaseous emissions and ash composition. Co-combustion tests were performed in an industrial steam boiler, using Greek lignite from Ptolemais reserve, waste wood, MDF residues and power poles. The results showed that co-combustion is technically feasible and it can meet strict environmental standards in relation to toxic gas and heavy metals emissions.