A new invasive species, the Japanese grape leafhopper, Arboridia kakogawana (Matsumura). is reported for the first time in Romania. Arboridia kakogawana is a serious pest of grapevine (Vitis vinifera L.) in East Asia (South Korea and China) and in Southern Russia (Krasnodar and Rostov regions) and Ukraine. In 2018, very high numbers of A. kakogawana were caught on yellow sticky traps in a vine plot in Romania in Northern Bucharest. Adults were trapped from early June to the middle of November. The dynamics of the adult population were measured using yellow sticky traps, and in 2018 four peaks were observed in the middle of July, in the first 10 days of August, at the beginning of September and in the first 10 days of October. The first overwintering adults appeared from the beginning of June. Foliar symptoms associated with the trophic activity of the leafhopper were observed on grapevine and Virginia creeper (Parthenocissus quinquefolia (L.)). Yellow sticky traps used in prior studies in the Bucharest area were re‐examined and the Japanese leafhopper was discovered on these, which leads to the conclusion that the species has been present at least since 2016 in this area. This is the first report of A. kakogawana in Romania and in the European Union.