GaPO₄ nanoparticles having hexagonal structure with different amounts of Eu³⁺ ions were prepared at 130°C based on precipitation method in glycerol medium. The  interaction between GaPO₄ nanoparticles and Eu³⁺ ions has been investigated using Eu³⁺ luminescence and ³¹P magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. Based on these studies, it is established that Eu³⁺ ions up to 2.5 at.% replace the protons of the hydroxyl groups attached on Ga³⁺ ions present on the surface of the nanoparticles and above 2.5 at.%, a separate EuPO₄ phase is formed. The anisotropy parameters derived from the side band intensities of the ³¹P MAS NMR patterns from these samples confirmed the surface ion exchange at low Eu³⁺  concentration (2.5 at.%) and EuPO₄ phase formation at high Eu³⁺ concentration (5 at.% and more). The increase in anisotropy at high Eu³⁺ contents has been attributed to the presence of paramagnetic EuPO₄ phase.