Abstract <p>This work is a predictive study performed via the full-potential linearized augmented-plane-wave (FP-LAPW) method implemented in the wien2k code in the density functional theory (DFT) frameworks. The objective is to determine the structural, elastic, electronic, magnetic and thermodynamic properties of new half-metallic Cr₂RbZ (Z = Sn and Pb). Perdew–Burke–Ernzerhof generalized gradient (GGA-PBE) approximation was used to treat the exchange-correlation potential. Results on lattice parameters, bulk modulus, elastic, energy band gap and magnetic properties are reported. The calculated lattice constants for Cr₂RbSn and Cr₂RbPb are 7.3705 and 7.5323 Å, respectively. The elastic constants for the cubic system (C₁₁, C₁₂, and C₄₄) and anisotropy are computed to prove the mechanical stability of these compounds. The electronic band structures and density of states (DOS) of the compounds indicate they are half metallic because of the existence of the energy gap in the minority spin (DOS and band structure), which yields perfect spin polarization. The total magnetic moment of 9.00 μ_B is mainly contributed by the Cr atom. The thermodynamic stability of these compounds are also determined. In addition the temperature and pressure effects on the bulk modulus, heat capacities, Debye temperatures and entropy are computed and discussed in details.</p>