Fishes of the genus Herichthys are the only representatives of the family Cichlidae to have colonized the Neartic region. In this study, we used DNA barcode of 64 individuals of the Herichthys bartoni species group to test the monophyly of the species and the efficiency of this tool to discriminate among species. The Bayesian phylogenetic tree and the neighbour joining (NJ) tree obtained from the Kimura two-parameter model (K2P) give similar topologies. DNA barcoding resolution was very poor (25%). Additionally, the low levels of genetic divergence among taxa preclude the use of threshold values as has been suggested in earlier studies.