This article illustrates the methods and findings of assessing the health risks of exposure to indoor particulate matter in the frame of the European INDEX-PM project [12]. The evaluation was performed by taking into account all sources and types of indoor particulate matter, and distinguishing it to particulate matter (PM) from outdoor origin, from indoor combustion, environmental tobacco smoke, indoor air particles of biological origin, indoor resuspended mineral dust particles, semi-volatile organic compounds, as well as secondary particles generated by indoor air chemistry. It comprises an outline of a state-of-the-art review of existing exposure and doseresponse data of indoor PM and focuses at deriving general and by-source risk characterisation and risk management options for reducing potential health effects associated with exposure to indoor PM.