Gas reburning is a NOx reduction technique that can be applied to different combustion systems. The influence of stoichiometry and dilution effects on the efficiency of the gas reburning process has been studied from an experimental point of view at a temperature of 1100 degrees C. Methane, ethane, and natural gas have been used as reburning fuels. The results obtained show that both stoichiometry and dilution level are very important parameters for the performance of the process.