Plasmodium floridense is a saurian malaria parasite common in the Anolis lizards of the northern Caribbean islands and the SE USA. In the latter area, it is found in two native lizards (Sceloporus undulatus and Anolis carolinensis) and in the introduced Anolis sagrei, which is native to Cuba. We measured parasite prevalence and parasitemia in the introduced anole at a single site in North Port, Florida over 5 years. Prevalence, based on microscopic examination of blood smears, was high year-round (45.6% of adult lizards infected) but was highest in the two December collections and showed significant variation over time. The parasitemia of the P. floridense infections was extremely low, however, with a median of only three parasites per 1,000 red blood cells in infected lizards. This combination of high prevalence and low parasitemia suggests chronic infections for individual lizards and an endemic prevalence pattern. Our study also underscores the need for long-term studies to establish overall prevalence in malarial parasite systems.