Biotransformations of alkaloids over the last decade have continued to encompass a wide variety of substrates and enzymes. The elucidation of novel alkaloid biosynthetic and catabolic pathways will continue to furnish new biocatalysts for the synthetic organic chemist. Furthermore, an improved understanding of the genetic and biochemical basis of metabolic pathways will also permit the engineering of pathways in plants and other heterologous hosts for the production of therapeutically important alkaloids. The combination of increasing commercial interest and advances in molecular biology will facilitate the availability of robust biocatalysts which are a prerequsite to achieve economically feasible processes for the production of alkaloid-based therapeutics.