We surveyed for the presence of the Northern Curlytail Lizard, Leiocephalus carinatus armouri, from Port Salerno, Martin County, FL, northward to the Indian River-Brevard county line to determine the extent to which this species occurs along the Florida East Coast. The geographic range of L. c. armouri appears to be uninterrupted along the coast from northern Broward County through Palm Beach County. The heavily modified coastal habitat provided this species with the open sunny conditions and cement analogues to the rocky substratum to which it is adapted. Its ubiquity, rate of geographic expansion, combined with its carnivorous habits and large body size, have long since set the stage for an extensive restructuring of the indigenous and exotic lizard fauna in a way that has not been seen since its initial establishment in Palm Beach County almost one-half century ago. Urban heat island effects notwithstanding, frost isotherms predict instability of populations north of Fort Pierce and just below Sarasota on the West Coast.