The present invention provides a method of producing α-santalene by contacting at least one polypeptide with farnesyl phyrophosphate (fpp). In particular, the method may be carried out in vitro or in vivo to produce α-santalene, a very useful compound in the fields of perfumery and flavoring. The present invention also provides the amino acid sequence of a polypeptide useful in the method of the invention. A nucleic acid encoding the polypeptide of the invention and an expression vector containing the nucleic acid represent part of the present invention. A non-human host organism and a cell transformed to be used in the method of producing α santalene are also part of the present invention.