In Assam, the coffee plantations are confined in Chirang, Karbi Anglong and Dima Hasao districts and also has the potentiality for expansion in the foot hill regions of lower Brahmaputra Valley and Hill agro-climatic zones of the state. Weed management is the biggest problem for coffee cultivation in the state and Mikania micrantha is one of the most problematic weeds in most of the coffee plantations. To quantify the infestation of the weed in and around coffee growing areas, a survey was conducted in five coffee plantations and 19 locations of other plantation crops as well as open forests covering an area of 355 km2 in Karbi Anglong district of Assam. M. micrantha infestation was negligible to low in coffee plantations, which received two rounds of manual weeding whereas, the infestation was moderate to high where only one manual weeding or no weeding was done. In open forest, the density of the weed was quite high. Among the coffee estates surveyed, the highest infestation of M. micrantha was observed in the estates surrounded by open forests and neglected other plantation crops which served as a good seed source for this weed.