The influence on power loss PTof applied tensile stress σ in amorphous (Co0.89Fe0.11)72Mo3Si15B10( ) and Co73Mo2Si15B10( ) ribbons with different induced magnetic anisotropy Kuis reported. The losses are measured under sinusoidal flux conditions at Hz, T and at Hz, T. Measurements are carried out on samples in a stress-relieved state and with magnetic anisotropies induced by stress or field annealing. At Hz, a minimum m Ptversus σ is observed. The σ-value ( ) corresponding to the minimum PTincreases with increasing |Ku|. At Hz, a minimum in PTversus σ is observed in the samples with induced magnetic anisotropy, whereas in the stress-relieved samiales. However, no correlation between and and Kuis possible from the present data.