Bonding in the recently synthesized transition metal pnictide MoNiP8, which contains an unusual cubic coordination of Mb and unique P-8 building blocks, has been analyzed by means of electronic band structure calculations using the semiempirical extended Huckel tight-binding method. Calculated densities of states suggest important covalent character for this compound, which is in good agreement with the experimentally observed electrical and magnetic properties. Departure from an ideal cubic structure for the Pg clusters present in this phase can be explained by the strong orbital mixing between these units and their environment in the solid.