Yacon (Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson) genotypes were planted under field conditions in the Czech Republic. Subsequently, a set of 25 genotypes was studied for variation in morphotypes, weight, saccharide content of tubers, disease and pest occurrence, DNA content, isozyme polymorphism, and phenolic content in leaves with the aim of finding the most suitable genotype(s) for industrial processing. A significant variation in tuber shape, weight, and content of glucose, fructose, sucrose, oligofructans and phenolics was found. The same was concluded for DNA content and leaf isozyme polymorphism. The results over the three growing periods showed that the most productive was genotype 68, with an average root tuber weight of 2.8 kg per plant, and genotypes 85 and 51, with 2.7 kg and 2.6 kg per plant, respectively. From the yield point of view, accession 48 was the most balanced. Significantly lower levels of glucose and fructose and higher levels of oligofructans in accessions 48 and 88 were noted compared to accessions 6 and 60. Accessions 6 and 60 had the highest content of phenolics. In the final part of the paper, yacon use in human nutrition, medicine, industry and commerce is discussed. Surprisingly, we conclude that yacon may be considered as a challenging crop for the areas outside the Andes.