The genus Psiadia Jacq. Ex. Willd. belongs to the Asteraceae family and includes more than 60 species, which are well represented in Madagascar and the Mascarene islands (La Réunion, Mauritius and Rodrigues). Several Psiadia species are used traditionally to treat various ailments such as expectorant for treatment of bronchitis and asthma, colds and abdominal pains. According to the literature, only a few species have been studied for their chemical composition. In order to make a comprehensive study of the genus Psiadia in the Mascarene islands, a chemotaxonomic study was conducted on 11 species endemic to La Réunion. The aim was to identify chemical markers by a metabolomic approach using GC-MS and GC-FID for volatile compounds and ¹H NMR for non-volatile compounds. The 11 studied species were collected from different locations and seasons in order to analyze the geographical or seasonal variability of the chemical profile of each species. This study led to two different classifications of the 11 species in terms of composition of volatile and non-volatile compounds.