The oca collection preserved in the CIP genebank is made up of 881 accessions collected in different locations in Argentina, Bolivia, Chile and Peru. Using passport information, ploidy level (tetraploids and octoploids), morphological characterization data (using the 16 most robust descriptors) and DArT (Diversity Array Technology) molecular markers on 481 accessions from the collection, a core collection consisting of 60 oca 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.