In this paper we report new chorological data for 20 alien plant taxa from the vascular flora of Romania. A total of 9 species (Campsis radicans, Euphorbia glyptosperma, Grindelia squarrosa, Impatiens balfourii, Oenothera suaveolens, Robinia × ambigua, Rudbeckia triloba, Sedum sarmentosum, Setaria faberi) are reported as new to the regional floras within the country. Oenothera pycnocarpa and Dittrichia graveolens are reported in their second and the third sites in Romania, respectively. For the remaining 9 species (Cytisus scoparius, Dysphania pumilio, Eleusine indica, Erigeron sumatrensis, Eriochloa villosa, Oenothera depressa, Paspalum distichum, Rosa rugosa and Sicyos angulatus), we provided new field data, to improve knowledge on their current distribution and invasion status. All taxa are neophytes, introduced either accidentally (11 taxa) or deliberately (9 taxa), more than half of which are currently invasive or potentially invasive in the country. [ABSTRACT FROM AUTHOR]