Siberian boreal forest fires burn large areas annually, resulting in smoke that releases large amounts of particulate emission into the atmosphere. We sampled aerosol emissions from experimental fires on three Scots pine (Pinus sylvestris L.) forest sites of central Siberia. Emissions from ground-based aerosol samples were 0.1-0.7 t/ha. This value represented 1%-7% of the total biomass (10-30 t/ha) consumed during the experimental fires. We were able to classify the chemical composition of 77%-90% of the mass of particulate fire emissions. Chemical analysis indicated that an average of 8%-17% of the particulate composition was of mineral origin. Carbonaceous aerosols created because of incomplete combustion ranged from 50% to 70% of the total aerosol mass. The fraction of aerosols containing elemental carbon (EC) (i.e., graphite, soot, and charcoal) was 7%-15%. As our samples were taken near the ground surface, these results represent freshly emitted fire aerosols that have not yet had time to react with atmospheric moisture or to undergo postfire chemical or physical-chemical changes. In a typical year, where 12 × 106 - 14 × 106 ha burn in Russia, we estimate that 3 × 106 - 10 × 106 t of particulate matter may be emitted into the atmosphere.