Addition of nanoparticles into swine manure was investigated as a possible measure to mitigate the emissions of hydrogen sulfide and ammonia from swine production facilities. Bench-scale experiments were conducted, followed by room-scale tests in controlled-environment chambers closely representing actual swine production rooms. Among the 12 types of commercial nanoparticles tested, zinc oxide nanoparticles achieved significant reduction in gaseous hydrogen sulfide and ammonia concentrations when mixed into the manure at a rate of 3 g zinc oxide nanoparticles per liter of manure slurry. Room-scale experiments showed that mean initial hydrogen sulfide concentrations of 596, 57, and 39 ppm measured at the pit, animal and human levels within each chamber, respectively, were reduced significantly to 5, 1, and 1 ppm, respectively, after the addition of zinc oxide nanoparticles into the manure. Effectiveness of the treatment was persistent in maintaining low hydrogen sulfide level up to 15 days after treatment application. Pig performance and manure nutrient properties were not adversely affected by the application of zinc oxide nanoparticles.