We report 323 new vascular plant species for the Sevastopol area, an administrative unit in the south-western Crimea. Records of 204 species are confirmed by herbarium specimens, 60 species have been reported recently in literature and 59 species have been either photographed or recorded in field in 2008-2014. Seventeen species and nothospecies are new records for the Crimea: Bupleururn veronense, Lemna turionifira, Typha austro-orientalis, Tyrimnus leucographus, xAgrotrigia hajastanica, Arctium x ambiguum, A. xmixtum, Potamogeton x angustifblius, P. x salicifilius (natives and archaeophytes); Bupleurum baldense, Campsis radicans, Clematis orientalis, Corispermum hyssopifilium, Halimodendron halodendron, Sagina apetala, Solidago gigantea, Ulmus pumila (aliens). Recently discovered Calystegia soldanella which was considered to be extinct in the Crimea is the most important confirmation of historical records. The Sevastopol area is one of the most floristically diverse areas of Eastern Europe with 1859 currently known species.