A condensed overview is given of the potential offered by bacteria, fungi and yeasts to produce a wide range of bioflavours and fragrances. A few commercialised processes are also discussed. The advantages of microbial processes versus chemical synthesis or extraction are outlined. Both de novo fermentation processes as well as bioconversions based on adding specific precursors/ intermediates to microbial cells or enzymes are illustrated via typical examples. Bottlenecks, which currently hinder a wider introduction of this flavour biotechnology, are indicated and some solutions are proposed.