Green synthesized nanoparticles (NPs) are widely used in various environmental applications due to efficiency, less cost and ecofriendly nature. Generally, the green synthesized NPs have a lot of environmental application such as waste water treatment, disinfectants, ion sensor such as heavy metal ion detection, dye removal etc. Many industries such as textile, leather, food, cosmetics, paper and pharmaceuticals industries are used several dyes and their released to the environment produces the hazardous and toxicity to the aquatic life, animals and mankind living in the ecosystem. Green synthesized nanoparticles are ecofriendly, non-toxic and promising methods for degradation of dyes. Plant sources materials act as reducing agents during synthesis of green synthesized NPs and play an important role on degradation of toxic products in reducing pollution in the environment. Photodegradation of the waste water pollutants is a simplest way to degrade pollutants or contaminants towards non-toxic substance. Green synthesized metal/metal oxide NPs are efficient photocatalyst to dyes degradation in waste water. Green synthesized NPs play an important role on ion sensation of heavy metals in the environment. Green synthesized AgNPs, CuO NPs, Au NPs, Pd NPs, PtNPs, Co NPs are widely used for detection of heavy metals such as mercury (Hg2+), Lead (Pb2+), Zinc (Zn2+), Cadmium (Cd2+), Arsenic (As2+), Copper (Cu2+) etc., dye degradation in textile industries, waste water treatment in the environment. Various green synthesized nanocomposites offer an efficient and cost-effective solution in preventing water pollution and improving the water quality of waste water. Plant derived green synthesized NPs have a unique property such as biodegradability, sustainability and biocompatibility and used as a bioremediation to control environmental pollution.