Data on the species diversity of vascular plants of The Middle Volga region are presented. The list of species is based on own research of the staff of the Laboratory of Problems of Phytodiversity of the Institute of Ecology of the Volga river basin of the Russian Academy of Sciences. All information is published in scientific journals or monographs. Herbarium specimens are stored in the Herbarium "Vascular Plants of the Volga river basin"(PVB), some doublets – in herbariums MW, LE, MHA, UPSU. Data processing was supported by a GBIF - FinBIF data mobilization grant for European Russia (Russia-02).