The grayling is certainly not one of the most spectacular and well-known river fish species in Central Europe. Few nature observers have ever consciously seen it in its typical habitats, even though it is one of the dominant species there. Just a few decades ago, it was found in astonishing numbers. In the meantime, it has experienced a dramatic decline across its entire distribution area. This alone should be reason enough to take a closer look at this species. The authors have been engaged for many years as fisheries biologists, fish breeders, and anglers with the grayling. The results of their own research are included in this monograph, along with the experiences of other grayling experts, and it is evident that one can also be enthusiastic about inconspicuous fish shapes if one knows them well enough. The reader will get to know them from both a zoological and a practical perspective.