Metalorganic chemical vapor deposition was used to grow N-rich side GaNSb alloys under different growth conditions, and, for the first time, a considerable amount of Sb was incorporated into the GaNSb. The amount of Sb increased as the growth temperature decreased, but the maximal Sb content seemed to be limited by the solid solubility of Sb in GaN. Absorption spectroscopy of the GaNSb revealed a strong absorption band below the band gap of GaN. The below-band gap absorption extended to 0.8 eV, which makes GaNSb a promising material to serve as an infrared absorption layer on GaN.