This study aims at characterizing different anaerobic digestion residues in order to evaluate their biodegradability. A full characterization (biochemical, biological, agronomical) was carried out on three types of wastes: waste water treatment sludges, food-processing effluents and agricultural wastes. Firstly, the comparison between non-digested and digested wastes led to state that digestates present close characteristics even if they result from very different input wastes. Besides, determination of some agronomic parameters established that digestates were instable products, rich in potential phyto-toxic compounds and that consequently they should not be used directly on soil as an agronomic product. Determination of other parameters (quantification of pathogens, phyto-toxicity bio-assays) should confirm the need for digestates post-treatment. Post-composting of anaerobic digestion residues should lead to a fully valorized product, i.e stable, mature and harmless to the environment. The determination of treatability indicators, like self-heating potential, air permeability or porosity, would lead to an optimization of the AD residues post-treatment by composting.