This review will give selected examples of topics of current research into plant secondary metabolism. Besides detection, isolation and characterisation of enzymes and genes involved in the formation of natural products, the structures of enzymes after crystallisation are now being investigated and this information gives us hints on the catalytic mechanisms as well as probable evolutionary origins of these enzymes. Manipulation of natural product formation is achieved by overexpression or down-regulation of genes encoding biosynthetic enzymes or regulators (transcription factors) as well as by transfer of those genes into foreign organisms (bacteria, yeast, plants). Techniques, strategies and methods are used to investigate plant secondary metabolism ensuring that this field remains challenging.