Pueraria lobata Kudzu is a perennial liana native in temperate to tropical East Asia. Introduced mainly as an ornamental plant into many (sub)tropical regions and as a forage crop in the South-Eastern USA it has spread vegetatively into adjacent forests and grasslands and has also been dispersed with garden waste. The objectives of this paper are: (i) to assess whether the ecology of P. lobata in Southern Switzerland is similar to that in the South-Eastern USA where it causes great damage; (ii) to predict its further spread in Southern Switzerland. In Switzerland it already occurs in 32 sites covering 16 200 m2; the shoots grow = 26 cm per day and = 11 m per year forming = 2 m thick mats. P. lobata infested sites contain about half as many plant species as similar sites without it. This paper shows that the ecology of P. lobata in Southern Switzerland is similar to that described for the USA. The broad climatic requirements of the species suggest that it could establish in many regions of Southern and Central Europe. However it is not expected to spread on a large scale in Switzerland because there appears to be no establishment from seed and because its stands are always near settlements and thus mostly controlled.