This work is devoted to the decomposition of gaseous HCN by oxidation with air catalyzed by different nickel containing catalysts. The presence of metallic nickel does not cause the decomposition of cyanide at 400°C, but NiO, electrochemical prepared nickel oxides Ni 2 O 3 ÁxH 2 O and (b,c)-NiOOH exhibit distinctly high catalytic activity at this temperature. The effect of HCN decomposition for electrochemically prepared nickel oxides was over 90 %. Nickel deposited on activated carbon also demonstrated catalytic behavior during the destruction of HCN with an air mixture at the temperature 400°C. Nickel oxide mixed with activated carbon showed a small increase of catalytic activity in the destruction of HCN in comparison with NiO.