Clay modification techniques have been employed to improve heavy metals adsorption properties of clay minerals for removal of the metals from their respective aqueous solutions. These modification techniques enhance the surface area, pore volume, and number of present active sites on the surface of the clay. In this study, recently developed and newly applicable techniques such as chemical, physical (thermal), biogenic and mechano-chemical treatments are reviewed and discussed as treatment techniques for modifying clay minerals. Intercalation and pillaring of clay minerals are chemical processes through which modification could be achieved. Surface doping and chemical grafting of polymer onto clay could produce superadsorbent materials with highly enhanced adsorption properties. Also, activation, structural transformation and disruption of clays could be achieved by thermal treatment. Eco-friendly mechanochemical method which eliminates the use of solvents is also used to achieve chemical processing and transformation of clay for adsorption purpose while biogenic modification which involves the fortification of clay with organic biomass and composites is a promising technique for modification and enhancement of clay for heavy metals adsorption. The adsorption properties of different modified clay minerals are also discussed in comparison with their raw (unmodified) form.