At the Nickel Research Center, a research was carried out to evaluate the pretreatment to the inlet water of the demineralisation process of The Ernesto Che Guevara Nickel Production Company, through the application of a cold softening, coagulation-flocculation and filtration treatment with the aim of reducing the consumption of regenerants of the cationic and anionic resins used in the process. Through runs at laboratory scale, 13 ,98% of the total initial alkalinity, 6,85% of the total dissolved solids, 8.33% of the total hardness and 1,79% of the silica were reduced; what was reversed in a saving of more than 50 % of the regenerants: sulfuric acid, soda and sodium chloride, which would bring a positive impact by reducing the release into the environment of these reagents.