On the basis of the researches led in the Laboratory SMS UR 3233 of the University of Rouen Normandie), together with recent publications on the subject, this talk reviews the most relevant Second harmonic generation (SHG)-based methods developped for the characterization of organic compounds. Several topics are addressed: chiral discrimination in the solid state, phase diagram investigations, characterization of polymorphic transitions, crystallization kinetics, coupling of SHG microscopy to other analytical techniques.