Introduced species are those species moved by humans from their native location to another location. Most often the species are introduced for agricultural or landscaping purposes or as sources of timber, meat, or wool. Invasive plants have often been thought to succeed because they have escaped their natural enemies, primarily insects that remained in the country of origin and were not transported to the new locale. In the 21st century, they have become a serious economic, social and environmental threat. Invasive plant species can spread rapidly with negative consequences for native species, have an impact on the diversity of local species, and also they affect water availability and damage the quality of soil nutrients. Once an alien species has invaded a habitat, it changes the conditions of that environment. The harmful effects of invasive species are recognized in many parts of the world and integrated strategies have been implemented to reduce current and future impacts. The proposed study aimed to list out the invasive alien plants of Calicut district, the second-largest urban agglomeration in the state of Kerala of state.