Effect of Pr and Co substitution on magnetic properties and magnetic entropy changes in the cubic NaZn 13 -type compound LaFe 11.2 Si 1.8 has been experimentally investigated. Replacing 30at.% La with Pr leads to a decrease of Curie temperature from 216 to 203K, and drives the magnetic transition from second-order to first-order. As a result, magnetic entropy change, under a field change of 0–5T, increases from 13.7 to 19.4J/kgK. Substitution of Co for Fe in La 07 Pr 0.3 Fe 11.2 Si 1.8 can adjust T C to around room temperature. A magnetic entropy change of 9.3J/kgK at T C =290K for a field change from 0 to 5T is obtained in La 07 Pr 0.3 Fe 10.4 Co 0.8 Si 1.8 . A reversible variation of magnetization with temperature and magnetic field is observed in the present compound, which is highly desired by the magnetic refrigeration application.