Biomass burning (BB) is a major source of pollutants that impact local, regional, and global climate, air quality, and public health. However, the influence of burning conditions and fuel type on emission factors of pollutants is still not well understood. Here, we present the results from a laboratory study of emission factors of pollutants from seven different sub-Saharan African biomass fuels combusted under a wide range of burning conditions ranging from smoldering to flaming. We found that particulate matter (PM) and CO emission factors (EF; g (kg wood)^-1) are highly sensitive to the burning conditions, with an order of magnitude variation between flaming and smoldering burning conditions. NO EF shows a fuel type dependence, with higher NO EF for fuels with larger nitrogen content. We observed a linear correlation between PM and CO EF and proposed that CO EF could be used as a proxy for estimating PM EF in cookstove emissions. The proposed relationship is valid regardless of the fuel type, moisture content, stove types, and origin of the fuel. Unlike total PM, EF of inorganic species do not show dependence on burning conditions. Finally, we showed that burning biomass fuels in a tube furnace would be an exceptional experimental approach to study BB emission under controlled burning conditions.