Metabolomics is a newly emerging field of "omics" research concerned with the comprehensive characterization of the small molecule metabolites in biological systems. It can provide an overview of the metabolic status and global biochemical events associated with a cellular or biological system. An increasing focus in metabolomics research is now evident in academia, industry and government, with more than 500 papers a year being published on this subject. Indeed, metabolomics is now part of the vision of the NIH road map initiative (E. Zerhouni (2003) Science 302, 63-64&72). Many other government bodies are also supporting metabolomics activities internationally. Studying the metabolome (along with other "omes") will highlight changes in networks and pathways and provide insights into physiological and pathological states. The concept of Systems Biology and the prospect of integrating transcriptomics, proteomics, and metabolomics data is exciting and the integration of these fields continues to evolve at a rapid pace. Developments in informatics, flux analysis and biochemical modeling are adding new dimensions to the field of metabolomics. To be able to walk from genetic or environmental perturbations to a phenotype to a specific biochemical event is exciting. Metabolomics has the promise to enable detection of disease states and their progression, monitor response to therapy, stratify patients based on biochemical profiles, and highlight targets for drug design. The metabolomics field builds on a wealth of biochemical information that was established over many years.