The presence of Dianthus roseoluteus Velen. species in Turkey is based on specimens collected from Antalya province. After the publication of Flora of Turkey, many specimens have been collected from Thrace (Kirklareli and Edirne provinces) that belong to this species. A comparison of the specimens collected from Antalya and Thrace revealed that they were morphologically different. The literature survey verified that the specimens collected from Thrace were Dianthus roseoluteus. The species collected from Antalya province is a new species, Dianthus macroflorus Hamzaoglu, and its description, pictures, distribution, habitat, and threatened categories are given. Its general morphology and seed micromorphology are compared with the related species, Dianthus roseoluteus. In addition to phylogenetic relationships between some closely related Dianthus species that belong to section Dentati in Turkey, Dianthus macroflorus and 13 additional Dianthus species sequences obtained from GenBank were examined with DNA sequence data from the nuclear ribosomal ITS region. These analyses were supported with morphological data.