Random amplified polymorphic DNA (RAPD) analysis was used to evaluate the genetic diversity of 10 flax cultivars. Flax cultivars showed varying levels of susceptibility to a set of pathogenic fungi. The tested cultivars were analyzed with four random decamer primers using the polymerase chain reaction (PCR). All the primers detected varying levels of polymorphism in all the tested cultivars. Cluster analysis by the unweighted pair-group method of arithmetic means (UPGMA) placed cultivars in several groups based on their RAPD-PCR banding patterns with overall similarity levels ranged from 4.05 to 94.72%. UPGMA also placed studied cultivars in several groups based on the patterns of susceptibility to a set of pathogenic fungi. The present study demonstrated that flax cultivars could be identified by their RAPD-PCR banding patterns, combined with their patterns of susceptibility to a set of pathogenic fungi. These results could be practical value for cultivar identification or for seed purity tests.