We present the spin polarized calculations on the new Zr2NiX (X = Al, Ga) alloys. Band structure analysis present them as half-metallic compounds with integral spin magnetic moment of 3 mB following the general Slater-Pauling rule. Thermal effects on some macroscopic properties using quasi-harmonic Debye model which considers the phononic effects, the effects of pressure and temperature are taken into account. The variations of the thermal expansion coefficient, Debye temperature, Gruneisen parameter γ and heat capacity for the compounds have been investigated for the first time. These thermodynamic properties may prove as a reference for their synthesis.