Abstract: Insecticides are biologically active compounds and an unintended consequence of its application may lead to significant changes in microbial populations and activities influencing microbial and ecological balance affecting soil fertility. In the present work, three bacterial isolates capable of degrading fipronil were obtained by enrichment from soil samples collected from the cardamom plantations of Idukki district, Kerala. According to the observations we found that the isolates were capable of growing in the presence of fipronil in two different growth media. Most of the microbes were grown maximum in rhizosphere and had the capacity to grow in the presence of fipronil. This study suggested that the fipronil insecticide causes transient impact on microbial populations at a recommended field application rate.