In the present paper, two SERS-active substrates (silver mirror and HNO3 etched Ag foil) were prepared for thiuram detecting and studying. SERS can provide the molecular vibrational model and structure information of thiuram at low concentration, thus providing very valuable information regarding the structure of the adsorbed molecules. This technique also allows for the in situ study of this molecule when adsorbed on a silver surface and the identification of the chemical state when they are adsorbed on the surface of silver substrate. The SERS study of thiuram was carried out at several adsorbtion concentrations, revealing that two different coordination complexes having different geometries (monodentate and bidentate) are possible adsorbed on the silver surface. These results have a significant importance regarding the understanding of the potential environmental impact of these molecules.