In order to determine the cytotypes of 67 accessions of Aegilops crassa from Iran, two flow cytometry and cytogenetics methods were applied. The nucleus of the young leaves was colored using DAPI and the intensity of fluorescent determined by flow cytometry. By comparing the intensity of the fluorescent of the Ae. crassa samples with Ae. tauschii (as an standard sample), two cytotypes 4x and 6x were identified. Cytogenesis study through flow cytometry confirmed the existance of two cytotypes, 4x and 6x, in the Iranian accessions. In tetraploid cytotypes the size of chromosomes ranged from 13.88±0.65 to 8.75±0.43 µm with a mean size of 11.21±0.20 µm per chromosome and a total genome size of 156.88 µm. All the chromosomes in these cytotypes were metacentrics except choromosome 4, 8 and 13 which were submetacentric with arm ratio of 1.70±0.10, 2.16±0.17 and 1.84±0.12 µm, respectively. Moreover pairs 4 and 10 were satellited chromosomes with the sizes of 1.33 and 2.19 µm, respectively, while, in hexaploid cytotypes the size of chromosomes ranged from 12.95±0.56 µm to 7.53±0.23 µm with a mean of 10.35±0.23 µm and total genome size of 217.39 µm. All the chromosomes in these cytotypes were metacentrics expect choromosome 3, which was submetacentric with arm ratio of 1.76±0.02 µm. Chromosome pairs 3, 6 and 10 were satellited ones with the sizes of 1.09, 2.09 and 1.54µm, respectively. The results of comparing of two cytotypes for evaluated morphological characteristics indicated that plant height, flag leaf length, color and wooly glums were significantly different between 4x and 6x cytotypes which could be employed for distinguishing these two cytotypes.