The compatibility of the entomopathogenic nematodes Steinernema feltiae and Heterorhabditis bacteriophora with 22 different pesticides was determined under laboratory conditions. The mortality of nematode invasive larvae and their virulence against the insect T. molitor were investigated. H. bacteriophora showed different sensitivity from S. feltiae to tested pesticides, especially at pyrethrum+piperonyl-butoxide. All tested pesticides caused decreasing of virulence of H. bacteriophora except fenpyroximate. This ingredient decreased the virulence of S. feltiae significantly. Also, tebufenpyrad decreased pathogenicity of S. feltiae. Based on the present study, we indicate that S. feltiae as well as H. bacteriophora are tolerant to most of the tested pesticides with some exceptions.