The existing and new findings on xanthohumol and other prenylated hop flavonoids are reviewed. First, synthesis of flavonoids and prenylated flavonoids in plants is described. The contents of major prenylflavonoids in hops in general and the xanthohumol contents in Czech cultivars in the last year are listed. Formulae of all the known hop prenylflavonoids and their chemical, physical and biochemical properties are given. Their effect on human health and their current and potential future utilization are discussed. Biotransformations of xanthohumol in microorganisms, mammals and humans are also mentioned. The balance of xanthohumol and isoxanthohumol in the production of beer is given.