Paulownia (Paulownia spp.) are trees originating from Asia, which are being planted all over the world because of the characteristics of their wood and their fast growth. The purpose of our research was to determine how widely this species has been planted in Bela krajina, Slovenia, to assess how successful the plantations are, and to identify any signs of invasiveness. We located 28 plantations with a combined surface area of 15.5ha and a total of 11,765 trees. Most were of the Shan Tong variety; only one farmer had planted the Bellissima hybrid. More detailed analysis was carried out at four plantations, three in their fourth growing season and one in the third, and the trees were identified as healthy. Across the four plantantions, the lowest average diameter of the trunk was 11.7cm, and the highest 12.6cm; the lowest average height was 6.5m, and the highest 7.8m. Cutting seedlings back after the first year reduces height and diameter increments at the beginning, but the cut seedlings catch up after three growing seasons and even overtake uncut seedlings in height growth. We did not find any signs of invasiveness, although we spotted some root suckers and fruits on several trees in one plantation. All the seedlings were provided with sterile certification at the time of purchase, which inhibits the uncontrolled spread of these trees.