We studied a population of Florida Box Turtles, Terrapene carolina bauri, from September 2002 to December 2003, in the Florida Keys at the southernmost limit of its range. Population structure was estimated to be 7.5% juvenile, 58.75% female, and 33.75% male, resulting in a female biased sex ratio (1 male:1.74 females). Population size was estimated at 39.9–114.4 turtles/6 ha in a pine rockland forest, with an estimated density of 4.8–10.2 turtles/ha. Males had significantly longer carapace and plastron lengths than did females. Comparison of data with other populations of T. c. bauri revealed similar morphological characteristics among populations although this southern population had higher mean body mass than did populations in the central parts of its range.