Oil mist in the submicron size range, i.e. aerosol consisting of oil droplets smaller than 1 μm, is emitted by oil lubricated gas compressors, metal cutting and engine crankcase ventilation, amongst other industrial processes. As this mist poses a risk to human health and the environment it needs to be removed from gas streams. Coalescence filters are commonly used to separate oil droplets from air streams and glass fiber filter media are used for applications where high efficiencies are required, for instance for compressed air preparation. Filter media are commonly chosen based on empirical values depending on the application, since little is known about the impact of structural characteristics of the media on the operating behavior of filters. Therefore, this projects’ aim is to characterize filter media in terms of their structural characteristics and surface properties and find correlations the pressure loss and efficiency of oil mist filters.