The γ′ single phase interdiffusion in selected pseudo-binary sections of the Ni 3Al-X (X=Cr, Fe, Nb and Ti) ternary alloys was studied in temperature interval 1173–1533 K in order to assess the influence of the site-preference of components upon their diffusion rate. It was observed that ( a) Higher fraction of Cr or Fe on Al sublattice leads to lower values of D̃ XX ( Ni) . ( b) Both Ti and Nb, preferring strongly the Al sublattice, show significantly lower interdiffusion coefficients than Fe and Cr. ( c) The equation D̃ XX ( Ni) = D̃ AlAl ( Ni) holds for Ti and Nb, whereas the relation D̃ XX ( Ni) > D̃ AlAl ( Ni) is valid for Cr and Fe. ( d) Activation enthalpy of Q ii ( j) shows a systematic decrease with increasing valence electron number of the alloying element i. ( e) Nb shows a transient behavior Q—it has low values of diffusion coefficient compared to its site occupation but also a low activation energy.