Aegilops cylindrica species (CCDD, 2n = 4x = 28) is one of the wild relatives of wheat and hence known as a valuable source of genes related to biotic and abiotic stress tolerance. In this study genetic variation of 66 Aegilops cylindrica genotypes collected from west and northwestern of Iran was evaluated using quantitative and qualitative morphological traits. The results indicated that glumelle (lemma) length and glume color traits had the highest variation as the quantitative and qualitative traits, respectively. The principal components analysis (PCA) indicated 6 components that first component justified %30.3 total variation. Flag leaf color and fluffiness had the highest contribution in this component and thus the first component named as the flag leaf component. The cluster analysis divided the studied genotypes into three groups.  Genotypes originating from west of Iran were included in the first group and genotypes from northwestern Iran were clustered into the second and third groups. It could be concluded that the high genetic variation among genotypes of Ae. cylindrica revealed in this study can be utilized to improve wheat particularly for tolerance to biotic and abiotic stresses.