Citron (Citrus medica) is considered as one of the four ancestral Citrus species and has been in use for thousands of years as a natural source for both aroma and insect repelling compounds. Citron leaves, fruit peel and flesh contain a variety of metabolites of the phenylpropanoid family (coumarins, furanocoumarins, flavonoids including anthocyanins) and isoprenoid family (mono- and sesquiterpenes, carotenoids, limonoids) involved in a variety of ecological functions. Chemotaxonomy of citron in the context of the Citrus genus demonstrates a metabolic profile different from pumelo, mandarin, oranges and grapefruit, but resembling lemon, in agreement with the available genetic and genomic data.