The flavonoidal alkaloids or flavo alkaloids build a quite special group of natural products, where the typical flavonoid backbone (two aromatic rings are combined with an oxygen heterocycle) is linked with a nitrogen containing moiety too. Several plants, containing flavonoid alkaloids, were applied in the traditional medicine for the treatment of various diseases, e.g., infections, cold, cough, inflammation, icterohepatitis, laryngalgia, etc. In this review, the most important flavonoid alkaloids (ficine, isoficine, capitavine, buchenavianine, aquiledine, isoaquiledine, cheliensisine, lilanine, phyllospadine, lotthanongine, vochysine, dracocephins, drahebephins, davallioside, prolinalin, kopsirachin, uncaringambiriine, etc.) and their isolation, structure elucidation, biosynthesis, biological activity, and syntheses will be detailed. The synthetic derivatives, e.g., the antitumor Flavopiridol (Alvocidib, Sanofi-Tolero) and P276-00 (Piramal) will be discussed too.