Artificial selection is extensively used to develop pesticide resistance in natural enemies. RAPD markers were used to estimate genetic relatedness between the parent and artificially selected hybrids of the egg parasitoid Trichogramma chilonis Ishii resistant to multiple insecticides (700ppm of endosulfan, 540ppm of monocrotophos and 20ppm of fenvalerate) and high temperature (> 40°C). Highly polymorphic markers could be identified through the primers OPF-1 and OPJ-20. RAPD marker from 15 oligomers clearly outgrouped the susceptible parent from artificially selected pesticide-resistant strains. The first group comprised the susceptible strain. The second group comprised the two subclusters, the first subcluster including the strain resistant to endosulfan and fenvalerate, multiple-insecticide resistant strain (MIRS) and high temperature resistant (HTR) strain while the second subcluster consisted of monocrotophos and HTR strains. The discriminating property of RAPD markers allowed differentiation of the resistant strain from the parental susceptible strain. Artificially selected resistant strains shared relatively high similarity (61-66%) with susceptible parent strain as per Jaccard's index.