The use of biomass for heat and power production is supported in many IEA countries since biomass as a renewable fuel can effectively substitute fossil fuels and consequently reduce fossil CO2. During biomass combustion, inhalable particulate matter smaller than 10 micrometres (PM10) can be generated which can cause adverse health impacts. CO2 mitigation strategy involving biomass therefore needs to consider potential health impacts and ensure low PM emissions. This report summarises the current knowledge on the health relevance of combustion generated PM, describes the mechanisms which can cause PM in biomass combustion, describes different particle types, and provides information on measures to reduce PM from biomass combustion. It is important to distinguish carbonaceous and inorganic pollutants as well as primary and secondary aerosols.