We report a study of the NMR of gallium impurities in YIG. In this magnetic system a nonmagnetic impurity is added to a ferrimagnetic host where the observed nucleus is located at the magnetic defect site. This nucleus is coupled to the surrounding magnetic ions by a transferred hyperfine interaction, similar in form to the Heisenberg interaction, giving rise to local impurity states. These local states have been of much theoretical interest in recent years. Spin echo techniques were used to measure the relaxation behavior of 71Ga and 69Ga in single-domain samples of Y3Fe5−xGaxO12 for x between 0.05 and 1.0. The observed linewidth at x=0.25 shows a strong inhomogeneous broadening due mainly to the interaction between impurity sites. T1 is very sensitive to concentration, ranging from 1 sec for x=0.25 to about 10 msec for x=1.0 and varies as 1/T for T between 1.9° and 4.2°K. In contrast T2−1 varies almost linearly with concentration and is temperature independent.