The incorporation of In into InGaAsN grown by MOCVD is known to reduce the incorporation of nitrogen. In addition, the most commonly used nitrogen precursors are all extremely inefficient. Growth of InGaAsN with NF3 as the nitrogen precursor is relatively insensitive to the addition of indium and has an incorporation efficiency much higher than dimethylhydrazine. The results from a study of four nitrogen precursors are presented, indicating that only NF3 is insensitive to the incorporation of In. The relative incorporation efficiencies for the four sources are also determined, indicating that the relative efficiencies are as follows: NF(3similar to)hydrazine>tertiary-butylhydrazine>dimethylhydrazine. We propose a simple model based on chemical reactions to account for the differences in incorporation efficiency. Published by Elsevier Science B.V.