This chapter gives an overview on the issue of aerosol-based emissions observed in post-combustion CO2 capture. Firstly, the evidence of aerosol-based emissions obtained from different pilot plant tests is presented. Unlike vapor-based emissions, which can be quantified and predicted based on the vapor pressure of the component, aerosol-based emissions are difficult to predict as it depends on several parameters. The key elements identified to explain the observation of aerosol-based amine emissions in PCC are discussed here. As the issue is being better understood, several countermeasures have been tested. Their efficiency in reducing aerosol-based emissions and possible disadvantages are summarized. The remaining knowledge gaps both from an understanding point of view as well as from a countermeasures point of view are outlined, and can serve as a basis for future research on this topic.