The onion is a widely distributed vegetable crop, which takes an important place in the vegetable production in Serbia. The traditional planting method is the one from sets. Old cultivars and populations and, in recent years, foreign cultivars are grown. The large variety of genotypes, including both domestic populations and cultivars, comprises the significant gene pool of this region. The onion collection of the Institute of Field and Vegetable Crops in Novi Sad is based on the populations and cultivars from the territory of the former Yugoslavia. This paper reviews 30 onion genotypes on the basic IPGRI descriptors (ANNEX I). Variability of the reviewed characteristics was determined by PC analysis. High variability values have been established for bulb skin color, bulb flesh color, bulb hearting and bulb skin thickness. The genotypes varied in bulb skin color as well as in bulb flesh color from white to dark violet. These two characteristics had the largest impact on clustering, with a single genotype being heterogeneous exactly for these two characteristics. [Projekat Ministarstva nauke Republike Srbije, br. TR 31030]