The phenylpropanoid metabolism in plants is an important source of numerous compounds of great importance in development and defense. In particular, flavonoids play a significant role as signal compounds, phytoalexins, UV-protectants, pigments etc. Numerous enzymes (PAL, CHS, CHI, CHR, IFR and many others) are involved in this branched metabolic pathway. The key enzymes of phenylpropanoid biosynthesis are phenylalanine ammonia-lyase (PAL), and chalcone synthase (CHS). Both enzymes (as well as some other of the pathway) are encoded by multigene families. The organospecific expression of different members of these families is presumably the key factor for the regulation of the entire pathway. Several cis-elements, and trans-acting factors have been already described, however it is too early to formulate the conclusive model of the overall transcriptional regulation of the phenylpropanoid metabolism.