The feasibility of using deep ultraviolet (UV) treatment for abatement of ammonia (NH3) in livestock and poultry barn exhaust air was examined in a series of laboratory-scale experiments. These experiments simulated moving exhaust air through an irradiation chamber with variables of UV wavelength and dose, NH3 concentrations, humidity, and presence of hydrogen sulfide (H2S). Ammonia, initially at relevant barn exhaust concentrations in air, was substantially or completely reduced by irradiation with 185 nm light. Reactions were monitored using chemiluminescence detection, gas chromatography with mass spectrometry detection, and Fourier transform infrared spectrometry, of which the latter was found to be the most informative and flexible. Detected nitrogen-containing products included N2O, NH4NO3, and HNO3. It was presumed that atomic oxygen is the primary photochemical product that begins the oxidative cascade. The data show that removal of NH3 is plausible, but they highlight concerns over pollution swapping due to formation of ozone and N2O.