The genus Brassica comprises economically important oilseed and vegetable crops. Diploid species in this genus are cytogenetically classified as A, B, and C genomes, whereas amphidiploids contain AB, BC or AC genomes. Oilseed rape (Brassica napus), a tetraploid species containing the AC genome is an important source of edible oil and dominates the world's cultivated Brassica. Polymorphic DNA in complex genome of agronomic crops can be detected using arbitrary primers and polymerase chain reaction (PCR). In this study, thirty accessions from USDA germplasm collection representing two Brassica species (B. rapa and B. oleracea var. virids) and fifteen cultivars (B. napus) from the national winter canola variety trials (NWCVT) were evaluated using 13 sets of random amplified DNA (RAPD) primers. The results indicated that 126 polymorphic bands ranging in size from 125bp to 4000bp with at least 10 polymorphic fragments observed/primer. The resolved PCR products yielded highly characteristics and homogeneous DNA fingerprints. A dendrogram obtained using unweighted pair group mean average (UPGMA) method of cluster analysis showed that most of the accessions were separated into their prevailing taxonomic species and genus groups. Taxonomic groups A, C, and AC are shown to be partially homologous. In addition to distinctive markers, also particular relationships among species were identified. Thus, our results show that RAPD-PCR analysis is a useful tool for taxonomic studies and molecular breeding.