Parthenium (Parthenium hysterophorus L.) has traversed the oceans to reach Andaman & Nicobar and Lakshadweep Islands of India in early 21st century, nearly half a century after its first report in Maharashtra state in 1955. Its entry might be on account of contaminated movement of food grains and other materials with Parthenium seeds from mainland through ships and airplanes. The weed has established in wastelands and community lands in some of the islands, hence there is lurking threat of its further invasion in other islands and into croplands. Public were less aware of its harmful effects due its new occurrence in the region. Competitive plant Senna tora was noticed in the islands during survey, and was recommended for Parthenium management on the road side. Physical removal was done involving people participation and was recommended for its management due to ban on using of chemicals. Bioagent Zygogramma bicolorata was not found in Andaman & Nicobar Islands in spite of its introduction in 2005 and 2006 for its biological control.