Abstract: The invention concerns a method of preparing preferably highly concentrated aluminum triformate solutions containing alkali metals and/or alkaline earth metals, by the neutralization of an alkaline aluminate solution containing alkali metals and/or alkaline earth metals by adding formic acid, and subsequently heating the solid precipitated to give a clear, stable aluminum triformate solution. The invention also concerns highly concentrated aluminum triformate solutions containing alkali metals and/or alkaline earth metals and the use of such solutions to impregnate textiles, in disinfectant and cleaning agents, as a coagulant for paints, or as a setting agent in leather processing.