Various molecular techniques are available to make differences and to study the genetic divergences among species and populations, of which the most efficient ones are PCR-based markers. One of these methods, molecular fingerprinting, enables the distinction of closely related populations. ISSR-primers are universal primers that can be used for such studies. The utility of these primers was tested for three populations of Eretmocerus mundus Mercet (Hym, Aphelinidae), a primary parasitoid of the whiteflies. Of the 60 ISSR primers, that were checked, as many as 64 bands were obtained from 16 primers. The band sizes ranged from above 200 to 1000 bp for different primers. The rate of divergence among the bands was strong enough to make a clear difference among the studied specimens; however the intricacy of using these primers is very much for studying the divergence among several populations. Therefore, sequencing of specific regions of DNA could bring more success to find out divergence among populations of these tiny parasitoids.