A summary of the latest available information on the formation and decomposition of nitrogen compounds in gasification, hot-gas cleaning, and gas combustion is presented. When nitrogenous fuels are gasified, nitrogen compounds are formed in gas from fuel nitrogen. In pressurized high-temperature fluidized-bed and entrained-bed gasifiers, NH3 is the primary nitrogen compound. Very little HCN is formed in these types of gasifier. The most important factors correlating with the NH3 content of the gas seem to be gas temperature and fuel quality. The NH3 content of the gas can be reduced by catalysts or by feeding oxidizers to the gas. CH4 reduces the decomposition rate of NH3.