Classification and differentiation of Bacillus anthracis isolates by genetic markers play an important role in the study of anthrax epidemiology. We have applied a PCR based method – Random Amplification of Polymorphic DNA (RAPD) to identify twenty-five B. anthracis genetic markers. These markers allowed for classification of the studied strains into five different groups. Three selected RAPD markers were cloned and sequenced. Typical integration of the three markers allowed for specific definition of the five RAPD derived genotypes. To test the universal power of these markers to discriminate between diverse B. anthracis strains, the nucleotide sequence of each marker was searched against all available B. anthracis genome sequences (both finished and unfinished). The three markers system could differentiate between strains belonging to the genetic groups Aβ, A1a, A1b, A4 and B1 (as defined by Keim et al., 2000; Maho et al., 2006) and gave rise to a unique combination for group A3, but couldn’t distinguish between the sub groups A3a and A3b. In addition, this system could not distinguish between groups B2 and C (identical three marker combination). In an attempt to improve the resolution of this system we introduced a fourth marker. In silico analysis revealed that the resulting four markers system could now differentiate between group B2 and C, adding a second genotype to groups A1a, A3a and A4. This four marker system could potentially provide an accurate, simple, and inexpensive agarose-based system for classification B. anthracis strains in laboratories involved in research of this bacterium.