The present study evaluated the leaching potential of biocides viz., Chlorpyrifos (organophosphate insecticide), Hexaconazole (triazole fungicide) and Imidacloprid (neonicotinoid insecticide) used in the paddy fields of kuttanad and their persistence in water. Leaching potential of biocides used in this experiment were in the order: Chlorpyrifos < Hexaconazole < Imidacloprid. All the three biocides used in this study viz., Chlorpyrifos, Hexaconazole and Imidacloprid were found to be persistent for more than 4 weeks. The results revealed that Chlorpyrifos, Hexaconazole and Imidacloprid used in the paddy fields of Kuttanad have potential to reach nearby aquatic systems and cause threat to a wide range of non-targeted organismsin the ecosystem including M. rosenbergii, prime species for export, earning overseas revenue for India.