Metabolomics is the science of small molecules. Metabolomics analyses are performed using an advanced set of analytical platforms designed first to separate and then to detect many 100s of metabolites that are present in an extract of a plant tissue. The technologies being developed for these large-scale, potentially unbiased analyses are greatly changing our way of thinking about what is possible in plant biology. We are applying both Liquid Chromatography and Gas Chromatography together with Mass Spectrometry to study the biochemical composition of contrasting plant materials. Metabolomics is already giving plant scientists deeper insights into the complexity of plant metabolism and plant metabolic composition than were ever possible before.