In the context of Alien Invasive Species (AIS) assuming worldwide importance as being the second most important irreversible impact on landscapes next to habitat destruction, the paper assesses their threat to the forests of Kerala. Based on field surveys and using a risk assessment protocol, the study identified 38 alien invasive species in the forests of Kerala. Of them, 10 are of high risk, 12 pose medium risk , 10 pose low risk and 6 insignificant as per the risk assessment conducted. There are 5 trees, 11 shrubs, 4 subshrubs, 12 herbs and 6 climbers among the alien invasives found in the forests of Kerala. The land of origin of the alien invasives happens to be America for 11 species, South America for 10 species, Central Ameriaca for 6 species, Central and South America for 4 species, and Asia for 3 species. One each of the alien invasives is from Africa, Australia, West and Central Africa and the West Indies. Most of the introductions into the forests of Kerala was intentional (31 species). Measures which would restore habitats from alien invasives and eradicate them which are in the establishment phase and prevent incursions of new invasives into the forest areas are discussed.

Key words: Alien invasive species, Risk assessment, forests of Kerala, habitat restoration