Structural proteomics is the application of protein chemistry and modern mass spectrometric techniques to problems such as the characterization of protein structures and assemblies and the detailed determination of protein-protein interactions. The techniques used in structural proteomics include crosslinking, photoaffinity labeling, limited proteolysis, chemical protein modification and hydrogen/deuterium exchange, all followed by mass spectrometric analysis. None of these methods alone can provide complete structural information, but a "combination" of these complementary approaches can be used to provide enough information for answering important biological questions. Structural proteomics can help to determine, for example, the detailed structure of the interfaces between proteins that may be important drug targets and the interactions between proteins and ligands. In this review, we have tried to provide a brief overview of structural proteomics methodologies, illustrated with examples from our laboratory and from the literature.