Nanotechnology is gaining curiosity in agriculture due to its exceptional chemical and physical properties, allowing plants to modify their genetic structure, lower agrochemical levels, and enhance resistance to biological and environmental stress. Nonetheless, warnings about the ecological consequences and toxic outcomes accompanying nanoparticles have been raised because of their escalated production and usage. Due to their distinct physicochemical properties, nanoparticles can engage with soil, water, and plants, possibly leading to unexpected environmental impacts. Various harmful effects of nanoparticles on plants have been noted, including stunted growth and decreased seed germination rates. Moreover, nanoparticles impact the cellular level by disrupting the formation of chlorophyll, damaging cell membranes, and affecting the electron transport chain in the mitochondria. Nanoparticles cause DNA damage and oxidative stress at the molecular level, resulting in cell death. One major source of nanoparticle contamination is soil, which also presents a potential threat to plants and soil microbial communities. Beneficial non-target insects may also exhibit altered behavior, survival, and reproduction upon nanoparticle exposure. In addition, aquatic ecosystems are at risk as rising quantities of nanoparticles (NPs) contaminate water and trigger adverse effects on aquatic organisms. In this chapter, we have shown the harmful impacts of NPs on plant ecology. In addition, we have presented potential ways by which nanoparticles cause toxicity in different agricultural environments, illustrating the complex relationship between nanoparticles and soil, microorganisms, non-target insects and water pollution in agriculture.