The present paper deals with the electronic properties of GaP and GaN zinc-blende/zincblende superlattices using the plane wave version of the full potential linear muffin-tin orbital (FPLMTO) method, which allows an accurate treatment of the interstitial regions. It is found that bowing, which is known to occur for ternary GaPN dilute nitrides, is absent from GaP/GaN 〞dilute nitride〞 superlattices with N concentrations greater than 7%, but it can be obtained in these same superlattices for high nitride concentrations.