Based on first principles full potential linear muffin-tin orbital method within the local density approximation, we have studied the structural, elastic, electronic properties and the behaviour under pressure on the magnetic moments per atoms from 0 to 85GPa for YFe 2 , NiFe 2 and YNiFe 4 intermetallic. The magnetic per formula unit value and equilibrium lattice constant of YFe 2 are calculated and compared with experimental data and theoretical results. However, this is the first predictive calculations for the structural and magnetic properties for NiFe 2 and YNiFe 4 compounds. From the computed elastic constants, theoretical value of Young’s modulus, Shear modulus, Poisson’s ratio and Lamé’s coefficients, sound velocities and Debye temperature are evaluated. Our results demonstrate that NiFe 2 , YFe 2 in C15 phase and NiYFe 4 in C15b phase are mechanically stable with the large bulk moduli B 0 =B VR for alloys containing atom Ni (NiFe 2 =224.7GPa and NiYFe 4 =192.0GPa). Finally, we have calculated the total and partial density of states for the three compounds. The partial density of states shows strong hybridization at Fermi level.