Entomopathogenic nematodes (ICRI-18, a strain of Heterorhabditis indica) are being used as biological control agent against pest Basilepta fulvicorne affecting cardamom plant roots. In this study, the impact of pesticides on the survival and infectivity of nematodes was investigated. The compatibility of Heterorhabditis indica with eight commonly used pesticides including profenophos, quinalphos, phenthoate, λ-cyhalothrin, chlorpyriphos, monocrotophos, triazophos and imidacloprid and fungicide Copper oxychloride were analysed. Freshly harvested infective juveniles from Galleria melonella cadavers were treated with the highest recommended concentration of the pesticides. Viability and infectivity of nematodes was analysed after 72 h of incubation at room temperature. Profenophos, triazophos and quinalphos severely reduced the nematode survival to 5-20% while Phenthoate, λ.-cyhalothrin, chlorpyriphos and monocrotophos reduced the survival rate to 70-90 % along with infectivity of nematodes and their offspring. However, Imidacloprid and copper oxychloride were found to be compatible with more than 90% survival and unaltered infectivity. Hence from this study it can be concluded that the organophosphorus class of pesticides was clearly found to have an adverse effect on H. Indica. Copyright © EM International.