Air in an 18-bird capacity broiler growth chamber was recirculated through a heated ceramic honeycomb coated with platinum and alumina throughout the production cycle for two batches of broilers. Ammonia concentration of the air inside the catalyst-treated chamber was always less than the ammonia concentration in a similar companion chamber not treated by the catalyst. Performance of the birds in the two growth chambers was similar. Energy considerations suggest a catalytic air-treatment system can reduce the energy required to control ammonia concentrations in broiler houses during cold weather, but can not economically replace all ventilation for ammonia control in situations where ventilation for ammonia control is an acceptable practice.