The present work studies the MILD (moderate or intense low-oxygen dilution) combustion behavior of syngas/ammonia/air. This study considers the variation of temperature distribution and pollutant emissions for different equivalence ratios, CO dilution, and ammonia addition. The results suggested that the MILD combustion technique can provide higher-level temperature uniformity and lower-level emissions by maintaining the same thermal efficiency. It was also demonstrated that equivalence ratio (φ) variations sensibly affect the MILD temperature structure and pollutant emissions. Under rich-burn conditions, infrequent oxygen molecules are more likely to react with NHi molecules due to their weaker bonds. Therefore, the presence of NH, NH2, and H radicals is more common. On the contrary, the abundance of oxygen molecules in lean mixtures results in O and OH radical generation. Regarding the pollutant emission issue, it was concluded that two primary NO generation mechanisms control the NOx quantity. Since both of these chain reaction mechanisms depend on O and OH content, the NOx production was intensified in the lean-burn mode. It was also revealed that changing the H2 and CO content has little effect on NOx generation. On the other hand, increasing the ammonia portion raises the NH2 production. The NH2 molecules react with O and OH radicals, producing higher amounts of NO. Therefore, the ammonia addition may result in an increment of NO. [ABSTRACT FROM AUTHOR]