In the production of nanoparticles, the bio-reduction properties of plant extracts are acknowledged worldwide to reduce the harmful effects of physical and chemical methods of synthesis of nanoscale metal particles. Zinc nanoparticles (ZnNPS) have been widely employed for various pharmacological applications. The present study recommends a green approach for the synthesis of zinc nanoparticles employing aqueous extract of stem of Lawsonia inermis. The biosynthesized ZnNPs were conformed visually by the appearance of white color formation in the mixture. The prepared ZnNPs were characterized by UV-via absorption, FTIR, SEM, XRD and AFM analysis. The UV-visible spectra showed that the absorption peak existed at 332nm. FTIR analysis revealed that phenolics, carboxylic acid, aromatic and amines present in the stem extract are responsible for the reduction and stabilization of the ZnNPs. SEM analysis demonstrated that the synthesized ZnNPs were spongy like shape. The XRD results indicated that the synthesized product showed hexagonal wurtzite phase and the average particle size is 17.80nm. The AFM image of ZnNPs exhibited a mixture of rod and spongy type of structure. The ZnNPS exhibited the antimicrobial activity against gram (+) bacteria, Bacillus thuringiensis, and Streptococcus faecalis: L. inermis may be used for the green synthesis of ultrafine nanoparticles of zinc for their antibacterial activities.