•Magnetocaloric effect of Ho3Pd2 is studied using Monte Carlo Simulation and ab initio.•We show that the Ho3Pd2 is electronically stable.•It has a ferromagnetic metallic with 84% spin polarization.•Total magnetic moment and the exchange couplings deduced from ab initio calculations.•Maximum value of the magnetic entropy was obtained. The binary intermetallic Ho3Pd2, crystallize in an U3Si2-type tetragonal structure with the tP10, space group P4/mbm (no. 127). On the basis of Monte Carlo Simulations and ab initio calculations, we have studied the magnetism of the Ho3Pd2 compound. We show that the Ho3Pd2 is electronically stable. It has a ferromagnetic (FM) metallic with 84% spin polarization. The exchange energy calculated between the magnetic configurations confirms that the ground state FM is more stable than the antiferromagnetic (AFM) states. The total magnetic moment and the exchange couplings are deduced from ab initio calculations lead, using Monte Carlo simulations, to a quantitative agreement with the experimental transition temperatures. The maximum value of the magnetic entropy change was obtained near the paramagnetic (PM)-FM transition at transition temperature 9.6 k equal to 18.60 J.kg−1.K−1 for magnetic field ΔH = 5 T. These results are more consistent with the experimental results. Our results suggest that this material is a promising candidate for applications in specific technological fields at low temperatures and moderate fields. The relative cooling power and adiabatic temperature change of Ho3Pd2 compound have been calculated for different values of magnetic field. The obtained value for ΔH = 5 T is 230 J/kg. Arrott plots analysis reveals that our materials exhibit a second order magnetic phase transition.