Pesticides are applied in various sectors such as agriculture, domestic, material building, personal and public health for control of weeds, pests, rodents; household and garden spray, control of animals and birds; incorporation of paints, glues, plastic protection sheeting; for application of clothing and skincare; and for control of malaria, dengue fever and cholera. In agriculture, chemicals are purposefully discharged into the environment. Application of pesticides in agriculture is a subcategory of the largest group of manufactured compounds used in the present world. Excessive and inappropriate use of pesticides has resulted in contamination of environment. Pesticides are degraded into organic micro pollutants that have negative effects on the environment. By the mechanism of biomagnification and bioconcentration, they cause deleterious effects on the living organisms. Ecological impacts of pesticides are different but they are chronic and inter-related. During precipitation, pesticides from land, float to aquatic systems and become harmful to fishes, birds, non-target creatures, etc. They also interact with injurious algal blooms, which enhances the original poisonous nature of the pesticides. This review focuses on environmental impacts of pesticides on contamination of water, fate, effects and behaviour in the environment, effects of contamination on natural resources, food safety, non-target organisms and threats to biodiversity. This study recommends application of suitable amounts of less harmful formulation of pesticides, as and when required.