Random amplified polymorphic DNA (RAPD) analysis is a simple and reliable method used to detect DNA polymorphism. Several factors can affect the amplification profiles, thereby causing false bands and non-reproducibility of the assay. In this study, we analyzed the effects of different concentrations of primer, magnesium chloride, template DNA and Taq DNA polymerase to develop and standardize a RAPD protocol for Centaurium species. The optimized PCR reaction mixture included: 50 ng of DNA extracted using a CTbased protocol, 2.5 mM MgCl2, 7.5 pmol primer and 2 U of Taq polymerase in a final volume of 25 ?l. Each of the five primers used in experiments (OPB11, OPB15, OPB18, OPF05 and OPH02) generated reproducible and distinguishable fingerprinting patterns of four Centaurium species. The obtained optimized RAPD protocol and the selected primers are useful for our further work in the genetic diversity studies of Centaurium species.