The ulluco collection preserved in the CIP genebank is made up of 548 accessions collected in different locations in Argentina, Bolivia, Colombia, Ecuador, and Peru. Using passport information, ploidy level (diploids, triploids and tetraploids), morphological characterization data (using the 19 most robust descriptors) and DArT (Diversity Array Technology) molecular markers in 354 accessions of the collection, a core collection consisting of 54 ulluco accessions was assembled. The most relevant components used to assemble the core collection were morphological and molecular diversity analyses. The collection location and the ploidy level of the accessions were additionally considered to expand the analysis in the preparation of the core collection.