Prenylated flavonoids are natural products that exhibit diverse biological effects and often represent the active components of various medicinal plants. This study demonstrated the production of prenylated naringenin by biotransformation using transgenic yeast expressing naringenin 8-dimethylallyltransferase, a membrane-bound enzyme, without feeding of prenyl donors. This method provides the possibility of generating prenylated flavonoids that occur rarely in nature.