Silene guicciardii (Caryophyllaceae) was rediscovered after field surveys carried out on Mt. Parnassos (Sterea Ellas, Greece), 160 years after the type collection made by J.B. Samaritani and J. Guicciardi in 1857. Since its first collection, it has been considered either as a distinct species, a variety or a mere synonym of the SW-Asiatic S. marschallii. We provide a revised description of the species and we re-evaluate its taxonomic position and that of the related species. We propose to treat the taxon guicciardii at the subspecific rank of S. marschallii. A color plate of S. marschallii subsp. guicciardii and a distribution map for all subspecies of S. marschallii are also provided. The name Silene guicciardii was lectotypified on a specimen preserved at G-BOIS, while isolectotypes are at G-BOIS, B, BR, C, GOET, JE, K and WU.