In this paper the role of sensory important trace components will be discussed. A chemical classification of the components is given as well as a review of methods of synthesis of the following substances applied in industry: cis-3-hexen-1-ol, rose oxide, alpha and beta-damascenone and damascone, theaspirone, raspberry ketone, pyranones, furanones and related products, alkylmethoxypyrazines, sulphur containing flavour substances.