Entomopathogenic nematodes (EPNs) have been used against especially soil borne insect pests. EPNs are feasible and attractive for biological control, because of their virulence against various insect pests, host seeking ability, being usable with standard equipment, and long-term efficacy. In addition EPNs can be applied simultaneously with some pesticides. These properties make EPNs ideal biocontrol agent in integrated pest management. In the present study, effects of 4 widely used pesticides (Glyphosate, Chlorpyrifos-ethyl, Captan, Fosetyl-al) on virulence and mortality of three EPN strains (Heterorhabditis bacteriophora Alman, H. bacteriophora HbH and Steinernema carpocapsae DD-136) were examined at 24 and 48 h periods. All strains were able to infect Galleria mellonella larvae averagely above 90 % rate, after 24 and 48 h treatments with all pesticides. However, some of the pesticides showed negative impact on the viability of the strains. Especially, DD-136 and Fosetylal seemed like incompatible, as the mortality rates were significantly higher than control for both 24 and 48 h. The results of the present study showed that it may be possible to use some EPN strains with some pesticides. It is expected that the results of the study will provide useful information for future integrated pest management programs.