Pulsed laser ablation under an O2/He glow discharge was studied to improve the surface crystallinity and UV luminescence of ZnO nanoparticles ∼10 nm in size. X-ray photoemission spectroscopy, scanning transmission electron microscopy, and cathodoluminescence spectroscopy were used to analyze the crystalline structures and chemical components. The results indicated that highly crystalline ZnO nanoparticles were fabricated under the O2/He plasma discharge. The near band gap UV emission intensities from these particles were roughly five times those of samples fabricated under O2 gas. The present results suggest the possibility of synthesize high quality ZnO quantum dots or nanoparticles without requiring any post-treatment.