The use of clay-based mortars is almost as old as mankind and they continue to be applied nowadays, namely indoors as plasters. That is because the environmental and technological advantages of clay-based plastering mortars clearly surpass their barriers and drawbacks. Selected aspects of the formulation, application, protection and use of clay-based plasters are presented and discussed here based on recent research. Ways of further increasing its environmental and technological performance are highlighted, with a view towards facilitating a broader use.