The present invention relates to a continuous process for the cyanation of hydrogenated .beta.-ketoesters in a cyanation zone maintained under conditions of temperature and pressure effective for cyanation of a hydrogenated R-ketoester. A substrate comprising a hydrogenated .beta.-ketoester is continuously supplyed to the cyanation zone together with a cyanide. The substrate is contacted with the cyanide in the cyanation zone for a period effective for at least partial cyanation of the hydrogenated .beta.-ketoester and a product stream is continuously extracted from the cyanation zone.