At the time of global warming and fluctuating climate is essential to use sustainable agriculture practices to preserve food security and prevent environmental damage. Therefore, scientists have discovered green synthesized nanofertilizers to improve crop productivity and minimize environmental damage. Nanofertilizers are newly developed fertilizers that have less negative impact on the environment and human beings because it is synthesized from plant extracts, microbes, and other natural products. Here, nutrients are encapsulated within the nanoparticles that help in controlled release and target specific. This advanced type of nanofertilizer is more commanding over the conventional fertilizers because it has more nutrient efficiency, improves soil and crop yield quality, and reduces the waste of fertilizers. Green synthesized nanofertilizers and plant growth promoters bring a new hope to the goals of sustainable development and modern agricultural techniques. Plant growth promoters are natural compounds that support plant growth and development through various methods, such as biostimulants, hormones, and biochar. They help in the nutrient absorption, enhancing root development, flowering, fruit ripening, cell division, and improving overall plant health. Addition of green-synthesized nanofertilizers in the agricultural practices as a plant growth promoter is a holistic approach to environmental sustainability. This chapter deliberates the various synthesis approaches for nanofertilizers, their mechanics, advantages, and future prospects.