When working on volatile compounds from plants, the objectives are multiples and can be summarized in four points: (1) Research of bioactive molecules, (2) Chemotaxonomic studies, (3) Applications in perfume industry, (4) Plant-insect interactions. Each of these four points will be discussed and illustrated by one or several examples of research projects conducted in the Chemistry Laboratory of Natural Substances and Food Sciences. The first two points exclusively concern volatile compounds generated by essential oils extracted from endemic or indigenous plants of Reunion, Mauritius and Madagascar islands. The two last points are dedicated to volatiles found in the airspace (headspace) surrounding flowers. This paper will also present a selection of sampling methods for volatile compounds that range from conventional, inexpensive, solvent-free, quick sampling methods to innovative methods, as well as an overview of detection and identification methods of volatiles including GC-FID and GC-MS.