The invention relates to the use of a composition containing aluminosilicates in combination with neutralizing agents and materials to obtain tanning hides in chrome-free tanning and retanning, in which the zeolites are aluminosilicates, neutralizing agents are weak acids and tanning materials, preferably syntans, are determined by their ability to bind to a collagen fiber of a skin and determine a tanning effect, the zeolite being present in a percentage range varying from 5% to 66% of the weight of the composition, weak acids being present in a percentage range varying from 5% to 33.3% of the weight of the composition and the tanning materials being present in the composition in completion of the total weight of the composition, with a minimum proportion of 5%, wherein the composition is used with the components already mixed prior to use, so that, during use, they act on the hides concomitantly.