This research work describes a novel green approach for the synthesis of ZnO nanoparticles at ambient/low temperature, where Ajwain (Carom – Trachyspermum ammi) seed extract functions as the zinc salt reducing agent. Different synthesis conditions provide control of particle size and size-distribution of particle formation. X-ray diffraction patterns confirm that ZnO nanoparticles synthesized with carom seed extract is a potential candidate for future experimentation and implementation in the biomedical field. The experimentally synthesized ZnO nanostructures were characterized using the field emission scanning electron microscopy (FE-SEM) and Powder Xray diffraction (PXRD) pattern measured with Cu Kα radiation. Moreover the photoluminescence (PL) measurements excited by the 380 nm line from the He–Cd laser were done at room temperature. The UV-Vis spectrum shows high absorption in the ultra-violet region at about 383.5 nm which makes the material to be suitable for UV filters. The average direct energy bandgap is determined as 3.490 eV. The scanning electron microscope study reveals that the morphology of the crystal is in the hexagonal shape. The average crystallite size is determined as 34.27 nm. The analysis of EDAX has shown the presence of zinc and oxygen. The FTIR study has shown the presence of Zn-O bond, C-O bond, C-H bond and metal oxygen bond.