Nuclear magnetic resonance (NMR) is a powerful tool for chemical and structural analysis. We have grown zinc-blende GaN using high-purity N-15 isotope gas by plasma-assisted molecular beam epitaxy and have studied the material using NMR measurements. We have detected, using NMR, optically pumped enhancement of N-15 nuclear polarization in zinc-blende Ga N-15. Initial NMR results of the optically pumped N-15 polarization in Ga N-15 are discussed. (c) 2006 Elsevier B.V. All rights reserved.