Abstract The anisotropic relaxation of differential thermal residual stress in WC-17wt.%(85Co-15Ni) cermets subjected to compressive plastic strain under monotonic and cyclic loading has been studied. Results were obtained via triaxial stress measurements using neutron diffraction. The residual stress in cylindrical specimens loaded uniaxially along the cylinder axis was observed to decrease with increasing plastic strain. Although relaxation occurred both perpendicular and parallel to the loading direction, i.e. radially and axially, it was observed to be greater in the radial direction and this trend was observed to increase with increasing plastic strain. A qualitative model for the observed behavior is proposed.