Skinks are successful colonizers and are commonly found throughout the Pacific islands, but introduced predators such as mongoose are known to threaten their survival. The two most abundant skinks found within the Fiji Islands are Emoia cyanura and E. impar. Abundance of these species encountered during visual transect counts on 16 islands within four habitats formed the basis of this study. Half of these islands had mongoose present, and the other half were known to be mongoose free. Our results showed that skink abundance under mongoose-free conditions was approximately five times higher than when mongoose were present. We conclude that it is very likely that mongoose severely supress even commonly found skink species across all the habitat types on these small islands, and it is likely that they impact even more severely on rarer species. Conservation actions that could protect these native species include bio-security mechanisms to prevent secondary invasion of introduced predators, habitat protection and management, and captive rearing programs. Failure to implement such actions is likely to result in even common species being at risk of extirpation.