Grinding aid additives are established in various industrial diy fine grinding processes, primarily to achieve either a) an increase of the production capacity, b) a decrease of the specific energy consumption or c) finer particles or a better product performance. However, even though numerous related scientific papers have already been published and a variety of grinding aids are currently applied in industrial processes, a comprehensive understanding of grinding aids is still missing. Thus, their selection and application is still mainly based on empirical knowledge. Therefore, this review gives a wide-ranging overview on grinding aids with special regard on their mechanisms of action, their impacts on the powder properties and the additive effects during lab-scale grinding. It is shown that the variety of applied substances, ground materials, target finenesses and analysis methods complicate the development of a comprehensive understanding, and how the mill type and grinding conditions influence the additive effects. (C) 2020 Published by Elsevier B.V.