Environmental pollution due to urbanization and rapid growth of industries has a damaging influence on human well-being and ecology. These industries use synthetic dyes that are now used in our routine life and are endlessly emergent in various important industries such as cosmetics, textile, paper, leather, paint, and food. The effluents discharged from these textile industries are highly colored and cause pollution, which consist of hazardous substances, including synthetic dyes, metals, chemicals. These hazardous substances after reaching to an open environment cause severe health risks to humans, flora, fauna as well as to microflora of water and soil ecosystems by interrupting the photosynthetic activity and causing eutrophication. It also affects the root and shoot length of plants, reduces seed germination level, and also constrains the microorganisms which are subsidizing the soil fertility rate. These created or generated pollutants are largely impervious to degradation processes and thus exist in the environment for a longer period of time. Thus, this chapter deliberates about the diverse applications of dyes in numerous industries and also about the toxicity hazards on different ecosystems.