The Bermudian rock lizard or skink Eumeces longirostris is categorized as Critically Endangered on the 2000 IUCN Red List. Skinks are vulnerable to habitat loss, introduction of non-native species and mortality caused by discarded bottles and cans that act as selfbaiting traps. This study describes the population characteristics of the Bermudian skink on two islands of the Bermudian archipelago: Nonsuch and Southampton islands. Nonsuch Island is a nature reserve but has populations of introduced lizards of the genus Anolis, lizard-eating birds and (a new finding) the cane toad Bufo marinus. Southampton Island is relatively isolated and has no introduced species. The skink population on Nonsuch Island was not investigated in detail, but appears to be small, localized to human habitation (where cover and food scraps are available) and dominated by large, old (some possibly >27 years) animals that exhibit high mutilation rates. Breeding occurs, but survival to adulthood appears poor. All of neighbouring Southampton Island was intensively trapped, with traps placed at the intersections of a 10-m grid. The population was estimated by mark–recapture trials to be c. 400 adults and juveniles; hatchlings are insectivorous and not susceptible to trapping. The population on Southampton Island is currently the largest known on Bermuda and appears to be viable; sustained isolation from predators and people is essential to its maintenance.