In present century, upgradation of agriculture is received a great attention because they satisfy daily needs in community and sustainable economic growth. Advantageous biological activities, offered by nanomaterials, open a new horizon in agriculture. In the context of agriculture, a great revolution is development and use of agrochemicals, such as nanofertilizer and nanopesticide. Activities of nanomaterials depend on (a) size, (b) shape, (c) morphology, (d) surface porosity, (e) composition, (f) redox potential, (g) charge in surface and (h) particle aggregation. Nanofertilizers are (a) better water soluble in soil, and easily available for seed and plants, (b) faster absorbed and assimilated by germinating seed and plant, (c) controlled delivery system for fertilizers and (d) with low fertilizer wastage due to leaching, degradation by biochemical reactions (hydrolysis, photolysis and decomposition) and gas forming. Nanofertilizers promote (a) seed germination, (b) plant growth, (c) chlorophyll formation, (d) photosynthesis rate and (e) stimulate the rhizosphere/soil microflora in agricultural field. Nanopesticides are (a) better soluble in water compare to conventional hydrophobic pesticides, (b) highly bioavailable and efficient to carry pesticides, (c) controlled delivery system for pesticides and (d) with low wastage due to degradation by ultra violet light, air, moisture, high temperature, biochemical reactions and rain fastness. Nanopesticides offer (a) antibacterial, (b) antifungal and (c) antiviral activities, and protect seeds and plants. In this chapter, information about development of nanofertilizers and nanopesticides, the mechanisms of biochemical activities and their applications in agriculture are represented in comprehensive way. It is expected that this chapter will grab lots of attentions from many research communities with different backgrounds.