The structural, magnetic and magnetocaloric properties of the mixed valent manganites Pr 0.6 Sr 0.4−x □ x MnO 3 (0≤x≤0.2) with perovskite structure have been investigated. X-ray diffraction (XRD) analysis using Rietveld refinement show that all our samples are single phase and crystallize in the orthorhombic structure with Pbnm space group. Strontium vacancy leads to a gradual increase of the unit cell volume. Paramagnetic (PM) to ferromagnetic (FM) transitions have been observed in all our synthesized samples. With increasing Sr-deficient amount, the Curie temperature T C decreases from 310K for x=0 to 170K for x=0.2. From the measured magnetization data of Pr 0.6 Sr 0.4−x □ x MnO 3 (0≤x≤0.2) samples as a function of magnetic applied field, the associated magnetic entropy change ΔSM close to the Curie temperature T C has been determined. The Pr 0.6 Sr 0.35 □ 0.05 MnO 3 compound (x=0.05) exhibits a maximum entropy change ΔSMMax of 4.81J/(kgK) at 260K in a magnetic applied field of 5T. ΔSMMax decreases to 4.17Jkg/K at 175K for x=0.2 in the same field magnitude. Large relative cooling power (RCP) value of 260.7J/kg is obtained for x=0.05 sample at a field change of 5T.