Nitrous oxide (N2O) is one of the important greenhouse gases. N2O emissions from anthropogenic sources are approximately 7-8 million tones N/yr worldwide and 70% of these emissions are caused by crop and animal production. In this study, direct N2O production from dairy cattle (enteric fermentation) and feces/urine temporarily stored in two freestall dairy barns were measured with 1) photoacoustic infra-red gas analyzer I (analyzer I, Innova 1412), 2) infra-red gas analyzer II (analyzer II: Teledyne API 320E), 3) GC-ECD (gas chromatography-electron capture detector),and 4) GC-MS (gas chromatography-mass spectroscopy). N2O concentrations in the exhaust air from the two barns ranged from 310 ppb to 371 ppb. No significant difference was found between GC-ECD and GC-MS N2O results. Analyzer II's response was not sensitive enough for the near ambient N2O concentrations found from the two dairy barns. Significant differences were found between GC-ECD and analyzer I N2O measurements. These differences may be caused due to interferences between N2O and CO2 and water vapor.