Odour and gas emissions from commercial swine lagoons were measured using a buoyant convective flux chamber (BCFC). Normal- and lightly-loaded lagoons were selected to determine the effect of loading rate. This paper contains data from the first 8 of 12 scheduled sampling visits. Odour concentration was evaluated by trained sensory panellists and dynamic forced-choice olfactometry. Odour intensity and hedonic tone were also evaluated by the panellists. Ammonia, hydrogen sulfide and carbon dioxide concentrations were measured from the Odour samples collected in 50-L Tedlar bags. The geometric mean Odour concentration of the BCFC inlet and outlet and of samples taken at the downwind berm of the lagoons were 82, 144 and 65 OU/m3, respectively. With 67% of the data collected, the mean Odour emission rates calculated for the two lagoons were 3.4+or-2.6 OU/s-m2. Gases emission rates were 98, 6.1, and 1.0 micro g/s-m2, for NH3, H2S, and CO2, respectively.