The structural, electronic, magnetic and thermodynamics properties of the NdFeSi intermetallic compound are studied using the full potential linearized augmented plane wave plus local orbital method, which is based on the theoretical framework of the density functional theory. We calculated the structural properties, in terms of the lattice constant, bulk modulus, first derivative of bulk modulus, and minimum volume. We calculated the electronic properties by considering the band structure, as well as the total and partial density of states. Electronic properties are confirmation that the NdFeSi intermetallic compound exhibits a metallic nature due to Nd-f state. The magnetic properties correlate with the magnetic moment. We determined that this compound's magnetic moment is 7.02610 μB. We investigated thermal behavior in terms of the Grüneisen parameter γ, the bulk modulus B0, the Debye temperature θD, and the entropy S with different temperatures and pressure ranges. All these results indicate that the NdFeSi compound is used in spintronic applications.