We have studied the magnetic and magnetocaloric (MC) properties of Ni 50− x Pr x Mn 37 Sn 13 (x=0, 1, 3, and 5) alloy ingots fabricated by arc-melting. Experimental results revealed a coexistence of the conventional and inverse MC effects in the samples with x=0, 1, and 3. There is a gradual decrease of the magnetization and magnetic-entropy change (ΔS m ) when Pr-doping content increases. However, the Curie temperature of the austenitic phase (TCA) around room temperature was not changed very much. Particularly, doping a small amount of Pr with x=1 enhances remarkably the linewidth of the peaks in its ΔS m (T) curves. This increases the relative cooling power (RCP) of Ni 50− x Pr x Mn 37 Sn 13 alloys when they are used as coolants in refrigeration devices. For example, under an applied field of H=50 kOe, the RCP increases from 150 for x=0 to ∼200J/kg for x=1. Higher Pr contents reduce quickly the MC effect because of the formation of nonmagnetic secondary phases.