In  the solution treated state Ni–Cr–Mo based alloys exhibit short-range order characterized by the appearance of diffuse intensity spots in electron diffraction patterns at {1 1/2 0} positions. This short-range order appears due to of the formation of chemical heterogeneities. In the present work we report on the investigation of short-range order in Ni–33 at % Cr and Ni–16.7 at% Cr–16.7 at% Mo alloys using transmission electronmicroscopy. Chemical heterogeneities and their sizes are analyzed by statistical methods applied to three-dimensional atom probe data obtained on the same alloys. The obtained chemical heterogeneities are correlated to regions of short-range order in Ni–33at% Cr and Ni–16.7at% Cr– 16.7 at% Mo alloys.