Closed loop feedback control is implemented in gaseous fuel staged burner to maintain low NO„ emission. The experimental set-up is a swirl-stabilized, diffusion flame, staged combustion gaseous fuel burner. The emissions of NO and carbon dioxide are monitored in real time and controlled as a function of burner load. The control input to the system is the . primary and secondary air flow rate. The NO,, emissions and CO2 concentrations are measured through two analyzers near the burner exit plane. This information is conveyed to a computer control system which invokes an optimization algorithm to maintain the low NO„ emissions in addition to high CO2 concentrations which, for fixed overall air/fuel ratio, entails achievement of high combustion efficiency. The success of the control methodology encourages its application on practical systems.