Abstract: The invention relates to a process for the removal of ammonia from gasification gas by selective oxidation in the presence of a solid catalyst. The oxidant used may be a mixture of oxygen and one or more oxides of nitrogen, e.g. nitrogen monoxide NO, whereupon gaseous nitrogen, water and possibly hydrogen are obtained as the result of the oxidation reaction. According to the invention, the catalyst used is aluminum oxide, which catalyzes the reaction within a temperature range of approx. 400.degree. C. 700.degree. C. The catalyst, made up of small particles, may be in the form of a solid or fluidized bed (12) in a separate oxidation reactor (11) subsequent to the gasifier (1).