Abstract: The catalytic properties of montmorillonite nanocomposites were investigated for dye removal. The catalytic activity of montmorillonite, a natural clay, was enhanced by modifying silver nanoparticles. Silver nanoparticles supported on modified montmorillonite (Ag-MMT) was successfully synthesis by wet chemical method. The obtained samples were characterized by XRD, TGA, UV–Vis spectroscopy, SEM-EDX, FTIR, and TEM. The synthesized Ag-MMT was used as a catalyst to degradation of dyes (methyl orange and methyl red) with sodium borohydride. Kinetic parameters (k) for the degradation reactions have been calculated and Ag-MMT has shown the high rate constant for this reactions of methyl orange and methyl red (8 and 10 min, respectively).