First principles calculations on structural, electronic, magnetic and elastic properties of BaNpO3 oxide are reported using full potential augmented plane wave method. To achieve the optimized lattice parameters, the local density approximation (LDA) and generalized gradient approximation (GGA) have been used. The calculated values of lattice constant and bulk modulus are found to be in agreement with experimental and other reported results. In addition, Hubbard approximation potential (GGA + U) and modified Becke Johnson approximation (mBJ) are also engaged for the exact prediction of band structure. Half-metallicity along with 100% spin polarization is reflected from the spin resolved band structures as well as densities of states. The ferromagnetic stable configuration of BaNpO3 perovskite is observed from the double cell optimization method as well as the spin-magnetic moment calculations. In addition, elastic constants have been calculated to envisage the mechanical response of this material. From these mechanical parameters, the ductile nature of the material is observed along with a Debye temperature of 356 K and melting temperature of 1968.71 K. (C) 2017 Elsevier B.V. All rights reserved.