The biotechnological generation of natural aroma compounds is rapidly expanding. Aroma chemicals, such as vanillin, benzaldehyde (bitter almond, cherry) and 4-(R)-decanolide (fruity-fatty) are marketed on a scale of several thousand tons per year. Their possible production by single-step biotransformations, bioconversions and de novo synthesis using microorganisms, plant cells or isolated enzymes is shown. The perspectives of bioprocesses for the oxifunctionalisation of lower terpenes by genetically modified organisms and economic aspects are discussed.