Pesticides when used carefully and in appropriate doses can be useful in agriculture to increase crop yield but excess and random usage of these can damage human health and cause unintentional complications throughout the world. Despite several advantages of using pesticides in agriculture, most of them pose a potential hazard to air, water and food that can lead to serious health problems for humans and ecosystems. Adverse effects pesticides to humans can be determined different animal models, but it is always a difficult task to evaluate the impact of these complex chemicals on the ecosystem. This book mainly focused on the bacterial reverse mutation test was conducted to evaluate the mutagenic potential of certain pesticide mixtures (Deltamethrin 1% + Triazophos 35% EC (D+T) and Profenofos 40% EC + Cypermethrin 4% EC (P+C)) on Salmonella typhimurium test strains by following pre-incubation method both in the presence and absence of metabolic activation system.