Nomenclatural notes on Cerastium siculum Guss. (Caryophyllaceae), a species described from Sicily and occurring in the central western region of the Mediterranean basin, are discussed. The names C. aggregatum Durieu ex Brign., C. densiflorum Guss., and C. siculum are lectotypified here. The taxonomic independence of C. siculum from C. semidecandrum L. and the other taxa of Cerastium L. sect. Orthodon Ser. subsect. Fugacia Fenzl is confirmed, as well as the synonymy of C. aggregatum and C. densiflorum.