A new species, Silene fetlerii D. Pavlova (Caryophyllaceae), found in the Eastern Rhodope Mts., Bulgaria is described. It is distributed in a limited area, mainly in screes and rocky places, and appears to be a new addition to the remarkable serpentine flora. Silene fetlerii belongs to the section Spergulifoliae and is morphologically defined mainly by the following features: anthophore shorter than capsule; small pyriform or 3-sulcate capsules; viscid stem nodes; and a greenish-yellow corolla. The plant is hermaphroditic. The differences between S. fetlerii and the morphlogically similar species are discussed.