Investigating the structure of a material is the first essential step in understanding its macroscopic properties. Getting insights of the interatomic and inter/intra-molecular interactions that influence the stability and the chemical behavior of a given compound allows its application in the best possible conditions and opens the way to design new materials with tailored properties. Neutron diffraction is a fundamental tool in structural characterization. Few examples concerning chemical crystallography, will be given to illustrate the properties that make neutrons the ideal probe for locating light atoms in the presence of heavy, electron-rich ones, and accurately determine atomic position and displacement parameters.