Industrial gas turbines fuelled by fossil fuels have been used widely in power generation and combined heat and power for many years. However they have to meet severe NOx CO and CO2 (greenhouse effect) emissions legislation in many countries. This paper reports a study on injection of small quantities of hydrogen in a hydrocarbon fuelled burner like additionally fuel to reduce the pollutants emissions. Hydrogen is injected in the primary zone, premixed with the air. Using this injection together lean primary zone, it is possible to reduce the NOx level while CO an HC levels remains approximately constant. The influence of hydrogen injection on CO, HC and CO2 emissions is mainly due to factors such as hydrocarbon fuel substitution and chemical kinetics. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.