The structural relaxation in (Ni,Fe)75Si10B15metallic glasses has been studied by measuring resistivity changes and Mo¨ssbauer spectra. The sign and magnitude of resistivity changes due to the relaxation depend strongly on the Ni/Fe ratio. The isothermal resistivity changes fit well the nonlinear kinetic form, indicating that the fluctuation of local environments of Ni and Fe atoms is very large and Ni and Fe atoms in Ni‐Fe‐Si‐B metallic glasses are mobile compared with Co and Fe atoms in Co‐Fe‐Si‐B metallic glasses. The compositional dependence and kinetic parameters for reversible resistivity changes and Mo¨ssbauer spectra strongly support that the reversible structural relaxation corresponds to the reversible short‐range ordering between Ni and Fe atoms.