Acoustic emission (AE), which has been successfully applied for monitoring a rather wide variety of solids elaboration processes, was almost never evaluated in the field of industrial crystallization for pharmaceutical or chemical products. Few papers reported that crystallization processes give rise to acoustic emission signals that could be related to the development of the basic crystallization phenomena. This study is intended to demonstrate new perspectives opened up by the possible use of acoustic emission (AE) as a non-intrusive and non destructive sensor for monitoring crystallization with a particular focus being put on real industrial processes. The preliminary results of the study will be reported in this work namely concerning the ability of the EA to follow the crystallization processes under different operating conditions and different types of crystallisation, and the obtained crystals in terms of particle size distribution and agglomeration degree.