Cirsium semzinanicum sp. nov. (Asteraceae) is described as a new species from Hakkari, Turkey. The new species is a part of the sect. Epitrachys (Cardueae) and similar to Cirsium karduchorum, from which it differs in morphological characters such as leaves, involucre, phyllaries, corolla, achens and pollen morphology. Geographical distribution, habitat and IUCN conservation status of this species are given.