Rietveld analyses of room‐temperature neutron powder diffraction data for seven Nd2(CoxFe1−x)17alloys (x= 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) are reported. In the ternary systems we find that thec‐type transition metal sites are preferentially occupied by Fe ions; concomitantly, thedandhsites have Co occupations larger than those predicted by stoichiometry, while thefsites deviate only slightly from random occupation. The magnetic moments obtained from the data refinements indicate a transition from a low to a high spin state on thed,  f, andhsites as Fe is incorporated into the structure; a reverse trend is exhibited by the moments on thecsite.