Healthy mice were orally fed with different doses of 3 types of pesticides namely, Metacid (organophosphate insecticide), Profenofos (organophosphate insecticide) and Nimbecidine (biopesticide). The doses were continuously given for consecutive 15 days. Control mice were fed with water. All the doses were given at the rate of 1 ml/100 g body weight. The genotoxic effects in pesticide-treated mice were assessed through the study of chromosomal aberrations, sperm head anomaly as against suitable untreated controls. The observations revealed that chromosomal abnormalities viz, chromosome fragment, somatic reduction, hypoploidy, hyperploidy etc. as well as abnormal sperm heads were found in pesticide-fed mice and maximum abnormalities were associated with Profenofos.