In this study, we report the chromosome number on the eight Cousinia species belonging to six sections distributed in south east and north east parts of Iran. Seven of the counts are new to science and one provides confirmation of the previous report. The results of this study are the first reports of the basic chromosome number within sect. Spinuliferae and sect. haussknechtianae. The present study reports x=12 for C. lasiolepis from sect. Alpinae which is new for the material originated from flora of Iran. The result of this study also confirmed the previously reported basic chromosome number of x=13 which had been supposed to be erroneous for sect. Leiocaules.