Tracer grain-boundary diffusion (GBD) of chromium Cr-51 in slightly hypostoichiometric (x A l < 25 at%) Ni 3 Al alloys containing several at. pct of Fe, Cr and Zr was studied using both serial sectioning and residual activity methods. Measurements of the product of the diffusion coefficient in grain boundary and the width of grain boundary, P, were carried out in the temperature interval from 773 to 1273 K. It was found that the addition of Fe and Cr up to about 6 at% does not alter the diffusion characteristics of Cr grain-boundary diffusion. The addition of a small amount of Zr, on the other hand, tends to increase the activation enthalpy and pre-exponential factor of Cr grain-boundary diffusion.