Nanotechnology is important and developing innovation with abundance of uses. It includes the blend and utilization of materials having one of the measurements in the scope of 1– 100 nm. A wide assortment of physico– synthetic methodologies are being utilized nowadays for the blend of nanoparticles (NPs). The size, orientation and physical properties of nanoparticles have reportedly shown to change the performance of any material. For several years, scientists have constantly explored different synthetic methods to synthesize nanoparticles. On the contrary, the green method of synthesis of nanoparticles is easy, efficient and eco-friendly in comparison to chemical-mediated or microwave mediated green synthesis. The chemical synthesis involves toxic solvents, high pressure, energy and high temperature conversion and microbe involved synthesis is not feasible industrially due to its lab maintenance. Since, green synthesis is the best option to opt for the synthesis of nanoparticles therefore the present research focuses on the cheapest and simplest method for the synthesis of Lead (Pb) Nanoparticles using the extract of Cuminum cyminum seed powder extract. The synthesized lead Nano particles were confirmed by UV – Visible spectroscopy, XRD, particle size analyzer. Results showed that lead nanoparticles size is of 87 nm and the synthesized nanoparticles were tested for their toxicity by studying their impact on germination of seed and their growth. The antimicrobial activities of lead nanoparticles were tested with pathogenic fungi, bacteria and photosynthetic algae. The synthesised nanoparticles showed efficient anti microbial activities against bacteria and pathogenic fungi. Similarly the synthesised nanoparticles showed efficient anti algal activity against Spirulina culture.