A semi-empirical interatomic potential of the Ni–W system is developed using a modified embedded-atom method (MEAM) formalism including second-nearest-neighbor interactions. The cross potential was determined by fitting physical properties of tetragonal Ni4W available in the literature. The MEAM potential was used to predict phase stabilities, lattice constants, and bulk moduli of nonequilibrium and equilibrium phases in the Ni–W system.