Distribution of the introduced scincid lizard Carlia ailanpalai Zug in the Federated States of Micronesia (FSM) is reviewed. It is common in open grassy areas but seldom occurs in mature forest. Preliminary surveys indicate that it is well established in Yap, though less frequently encountered at increasing distance from Colonia, the main settlement, and it is unrecorded in the extreme northern and southern parts of Yap. It is the most common species of lizard in open, grassy, ruderal habitats throughout Weno Island, Chuuk, being nearly the only species encountered in the commercial district, but it is unknown elsewhere in Chuuk State. The only record for Kosrae is a single specimen collected in 1988 (first record for the FSM), but there is no evidence of an established population. There are no records for Pohnpei State. Guam is likely the primary source for the Yap and Chuuk populations (and Kosrae specimen), but the time of initial introduction is unknown. Carlia ailanpalai appears to have spread rapidly, at least on Weno, Chuuk, where it has become the predominant lizard in open habitats islandwide, possibly since the late 1960s. How C. ailanpalai interacts with other species in the FSM requires further study, but preliminary surveys of distribution and relative abundance suggest that it has a negative impact on populations of Emoia jakati and, to a lesser extent, on other Emoia species as well. Populations of C. ailanpalai in the FSM meet the criteria for invasive species status as it is defined by numerous U.S. government agencies and international conservation groups.