The increasing rate of waste generation and the problem associated with its disposal poses a significant threat to the environment and human health. A commonly adopted method for the disposal of waste is landfilling. The geosynthetic clay liners (GCLs) have been widely used as hydraulic barriers owing to their high swelling capacity and low hydraulic conductivity. Yet some of their limitations have promoted for the development of polymer-modified GCLs, which can meet the ever-growing demand of GCL applications. This talk aims to comprehend the recent advances in the treatment of montmorillonite-based clays used in the manufacturing of geosynthetic clay liners.