Raman spectroscopy has now gained market acceptance as a robust, rapid and specific materials identification tool. The last decade has seen the release of a new generation of portable instruments that take the technique out of the laboratory and into the field or production site. However, a major limitation of conventional Raman spectroscopy is a lack of sensitivity for the identification of analytes in solution, preventing the application of this technique in addressing some important problems of relevance to the pharmaceutical industry. This lack of sensitivity can be overcome through the use of surface enhanced Raman scattering (SERS); with this technique, interactions between the analyte and an appropriate SERS substrate cause the weak Raman signal to be amplified by many orders of magnitude, allowing detection levels as low as parts-per-billion (ppb). Sample preparation is rapid and easy to perform, but quantitative procedures have been difficult to develop due to a lack of reproducibility in substrate manufacturing. Now that this problem has been overcome, there is considerable scope to develop new applications.