The present work is focused on synthesis and characterization of Zinc oxide nanoparticles (ZnO NPs) to study its effects on two Brassica juncea cultivars stressed with different toxicity levels of Cadmium (Cd). ZnO NPs were synthesized by chemical precipitation method and characterized using X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive Analysis of X-rays (EDX) techniques. Crystalline size was calculated from the XRD results using Scherer equation. In present study ZnO NPs suspension were used as priming agent for ameliorating Cadmium toxicity in B. juncea seeds under in vitro conditions. It was found that ZnO NPs treated seedlings displayed good growth characteristics over control and was able to overcome Cadmium toxicity in Brassica juncea , demonstrating a positive effect of the nanoparticles treatment.