The Florida Worm Lizard (Rhineura floridana) is the only extant representative of the suborder Amphisbaenia occurring in the United States and the only living representative of the Rhineuridae. We updated the known distribution of this species from 510 records with known localities. We further examined geographic genetic structure within this species using 1360 bp of mitochondrial DNA sequence data from 18 samples of R. floridana. Our results suggest an ancient divergence between populations in the north-central Florida peninsula from populations in the south-central peninsula. High genetic distances are observed within south-central populations, whereas genetic structure within northern populations is less discrete and characterized by much shallower divergences. Our findings suggest that south-central populations may be candidates for taxonomic recognition (or recognition as distinct management units) if additional genetic and morphological data support our results.