Imagine a world with no mystery illnesses, no diagnoses of exclusion and happy owners. Realistically, this is unlikely to happen in our lifetime. However, the promising new science of metabolomics may lead to a future of fewer medical mysteries, improved diagnostic criteria and better outcomes for some of the more frustrating cases. Metabolomics allows for hundreds of metabolites to be measured and then analysed using specialist techniques to equate what is being seen phenotypically with what is happening biochemically. Its potential for use by vets is currently limited to research, but in the future it may find its way into the clinic as a potential diagnostic aid. This article defines aspects of metabolomics, explains the basics of metabolomic studies and discusses the potential benefits of the technique to veterinary science.