The polymerase chain reaction (PCR) and restriction fragment length polymorphisms (RFLPs) of SrRNA gene of Argas species (~1800 bp) is a very useful technique for differentiation of Argas persicus, Argas hermanni and Argas arboreus species. The PCR/RFLPs profile of EaeI and EcoRI restriction endonucleases were highly characteristic of the genetic interspecific levels and low genetic intraspecific levels of the three species. Other enzymes proved that A. persicus and A. hermanni may be a single or monophyletic species (SacII and SstII restriction endonucleases). AvaII restriction enzyme showed that A. hermanni and A. arboreus could be a monophyletic species. AvaI restriction endonuclease was the only restriction enzyme to prove that the three Argas species may be polyphyletic species and identified uniquely by this enzyme.