Anaerobic digestion is a well-established technology for stabilising and converting organic waste into bio-energy and carbon-nutrient solid liquid solution applicable as fertiliser. The anaerobic digestion process must face challenges like process stability due to the accumulation of volatile fatty acids (VFAs) which contribute to the inhibition of the methanogenesis phase. Among the available strategies to improve anaerobic digestion efficiency and stability, the addition of biochar has attracted growing interest owing to its porosity, adsorption capacity and pH-buffering effect, as well as its potential to promote direct interspecies electron transfer, particularly when its surface is enriched with iron. This work aims to assess the effect of different biochars on anaerobic digestion performances, in terms of methane yield, process kinetics, and quality of the resulting digestates.