The kinetic behavior of Co2+, Cu2+, Cd2+, Cs+, and Pb2+ in the H-form of polyaniline silicotitanate composite as cation exchanger was studied as a function of particle size, concentration of the exchanging ions, reaction temperature, and drying temperature. The exchange rate was controlled by particle diffusion mechanism as a limited batch technique and is confirmed from the straight lines of B versus 1/r(2) plots. The values of diffusion coefficients, activation energy, and entropy of activation were calculated and their significance was discussed. The data obtained have been compared with that reported for other organic and inorganic exchangers.