In this study, we report genome size (C-values) estimated using flow cytometry for 18 taxa of Asteraceae from Turkey, 17 of which are here assessed for the first time. The studied taxa belong to the genera Achillea (one species), Anthemis (one subspecies), Tanacetum (four taxa) and Crepis (12 taxa). Additionally, chromosome numbers of nine taxa of Crepis are provided, four counts being new reports and the remainder confirming previous data. The 2C-values of the studied taxa range from 2.08 to 11.06 pg, which represent more than fivefold variation. The systematic and evolutionary significance of genome size is discussed within the framework of the results obtained in this study.