Technomyrmex difficilis is an Old World arboreal ant that is becoming a major pest in the US and the West Indies. After its first records in the New World in 1986 from Florida, T. difficilis was soon reported from other parts of the New World, including eight West Indian islands (Puerto Rico, New Providence, Grand Cayman, St Croix, St Thomas, Antigua, Nevis, and Jamaica) and Honduras. In Florida, T. difficilis has become one of the most common species found nesting in red mangroves (Rhizophora mangle). Here, we report records of T. difficilis nesting in red mangroves at 16 sites on eight West Indian islands, including four islands with no previously reports of this species (Grand Bahama, St Maarten, Roatán, and Trinidad). It is probable that over the next few years T. difficilis will become increasingly important as a pest in Florida and the West Indies.