Several reports indicate that many chemical pollutants which are widely spread in the environment, such as insecticide, pesticide and drugs are mutagenic in various test system. These findings reflect an urgent need to draw more attention to the possible genetic hazards of such pollutants to public health. The present investigation of working hypothesis deals with the effects of two insecticides viz. Methyl Parathion (MeP) and Diazinon (DZ) on non-target organism Drosophila melanogaster. We have carried out the chromosomal aberration test with various concentration for insecticides (MeP and DZ) which infer properties like ectopic pairing, inversion loop, puffing, fusion, and asynapsis. Chromosomal aberration result shows significant effects with DZ even in less concentration (0.02ppm) when compared with MeP (0.2ppm). The present study proposes that diazinon is more cytotoxic than methyl parathion in Drosophila melanogaster.