Grain boundary regions in B-doped as well as B-free Ni3AI were studied by field-ion microscopy and atom probe microanalysis. In the ductile, recrystallized, Ni-rich alloys the segregation of boron was often accompanied by an enrichment of nickel. Such an enrichment was not observed at boundaries in B-free alloys. Boron was also observed to segregate to the boundaries in a 25.2A1 - IB alloy which was reported to contain boron clusters. Such clusters were not observed, instead a high concentration of boron pairs were found.