The structural, elastic, electronic, bonding and optical properties of Ni3In intermetallic compound are examined using the full potential linearized augmented plane wave (FP-LAPW) technique in the context of the Perdew, Burke and Ernzerhof’s generalized gradient approximation (PBE-GGA). We have found that the Ni3In intermetallic compound in phase I has a negative formation energy (???? 46.26 meV) in contrast to phase II which has a positive value (2131.1 meV). This indicates that the phase II is not possible to exist in nature. The brittleness/ ductility behavior of the Ni3In intermetallic compound in phase I is discussed via the elastic properties. We calculate the density of states (DOS) and charge density. Our findings are that the Ni3In has a ferromagnetic ground state with a magnetic moment of 0.742 μB, and the bonding in Ni3In is dominantly ionic in nature. The dielectric function, refractive index, absorption coefficient, extinction coefficient, reflectivity, energy loss function and optical conductivity of the optical spectra are examined with regard to the computed electronic band structure.