Odour and hydrogen sulfide (H2S) emissions were measured on ten swine farms in southern Manitoba between May and October in 1999 and 2000. On each selected farm, air samples were taken from barn exhaust fans and manure storage. Odour concentrations of collected samples were determined by using a dynamic-dilution olfactometer. A JeromeTM meter was used to measure H2S levels of air samples from six farms. The average odour concentrations from barn exhaust ranged from 131 to 1842 OU/m3 and odour emission rates from 12 to 39 OU/s per m2 of floor area. No apparent correlations were found between the odour concentration and the general farm characteristics, such as years of operation, type of operation, ventilation system, and manure handling system. The average H2S levels spanned from 148 to 927 ppb on the six farms and H2S emission rates from 6.4 to 25.1 mg/s per m2 of floor area. Outdoor temperature had a significant effect on odour concentrations from barn exhaust, but not on odour emission rates (in a range from 12 to 35 degrees C). The odour concentration measured within 10 mm of the manure surface was the highest in May and the lowest in July in earthen manure storages. Low odour concentrations were measured in an earthen manure storage with straw cover that formed a thick crust on the manure surface.