Effect of Fe-substitution on the phase formation, partitioning behaviour of Fe in the co-existing phases, magneto-structural transition, magnetic entropy change and associated hysteresis losses has been investigated in Gd 5 Si 2 Ge 2 alloy. The virgin alloy crystallizes in monoclinic Gd 5 Si 2 Ge 2 -type phase, while Fe-substituted alloys form mixed monoclinic Gd 5 Si 2 Ge 2 -type and orthorhombic Gd 5 Si 4 -type phases. Electron probe microanalysis reveals that Fe does not dissolve in the matrix, but influences the magneto-structural transitions. Magneto-structural characterization of the Fe-containing alloys reveals that the Fe-substitution suppresses the structural transition observed at 273K in virgin alloy. A maximum magnetic entropy change, ΔS M of 6.5J/kg-K at 273K was observed for a field change of 2T in Gd 5 Si 2 Ge 2 alloy. The Fe-substituted alloys exhibit lower value of ΔS M but with reduced hysteresis losses.