Genomics and proteomics have contributed much to our basic understanding of toxicology, but have not provided all the information necessary to understand mechanisms of toxicity, or diversity in toxicological response to environmental exposures. A promising new technology is that of a metabolomic, which refers to the systematic study of the small-molecule metabolite profiles that result from exogenous stimuli, including exposure to environmental toxicants. The emerging field of metabolomics offers great promise for the development of early biomarkers of toxin exposure.