Stoichiometric GdZn crystallizes in the cubic CsCl-type crystal structure and has been reported to order ferromagnetically at 270 K. Experimental measurements of the magnetization and heat capacity of GdZn as a function of temperature and magnetic field confirm the ordering temperature and the type of magnetic order. The calculated magnetocaloric effect (in terms of the adiabatic temperature rise, ΔT_ad, and the isothermal magnetic entropy change, ΔS_mag) peaks at 270 K and reaches values of 6.5 K (−7 J/kg K) and 10.5 K (−11 J/kg K) for magnetic field changes of 0 to 5 and 0 to 10 T, respectively. The maximum magnetocaloric effect in GdZn is approximately 30% smaller than that observed in pure Gd, which is consistent with the amount of non-magnetic Zn in the intermetallic compound. Modeling of the magnetocaloric effect of different two-phase alloy compositions, including the eutectic composition alloy (50 mol.% GdZn + 50 mol.% Gd), indicates that Gd-Zn alloys with less than 50 at.% (∼30 wt.%) Zn can be used as high performance active magnetic regenerator materials. Both Gd and GdZn are magnetically soft showing negligible magnetic hysteresis. The behavior of ΔT_ad and |ΔS_mag| can be adjusted between two boundary conditions: (1) ΔT_ad and |ΔS_mag| decreasing almost linearly from ∼300 and ∼270 K, and (2) ΔT_ad and |ΔS_mag| remaining practically constant over the range ∼300 to ∼270 K. This ability to adjust the magnetocaloric effect properties allows one a flexibility in designing different refrigeration cycles and highly effective regenerator materials. A possible application for these alloys is for climate control magnetic refrigeration devices and refrigerators/freezers. Alloying Gd with Zn significantly reduces melting temperature of the alloys (the eutectic alloy melts at ∼860°C) compared to that of pure Gd (1313°C) and also improves the ductility over the GdZn intermetallide. This should simplify their fabrication into useful shapes (spheres, thin sheets, wires, etc.) for magnetic regenerator beds.