The aim of this study was to investigate the equilibrium swelling and sorption properties of a series of chemically cross-linked highly swollen hybrid composite hydrogel systems containing polysaccharide/clay polyelectrolyte based on the acrylamide/zinc acrylate and xanthan gum and clay such as sepiolite and these composite hydrogel systems were synthesized with free radical solution polymerization by using ammonium persulfate/N,N,N',N'-tetramethylethylenediamine as a redox initiating pair in the presence of poly(ethylene glycol) diacrylate as a cross-linker. Swelling experiments were performed in water at 25°C, gravimetrically. The hydrogels, the semi-interpenetrating polymer networks, and the hybrid composite hydrogel systems that were synthesized in this study have shown high water absorbency. Some swelling and diffusion properties were calculated, and they were discussed for the hybrid hydrogel systems prepared under various formulations. The equilibrium swelling ratio of chemically cross-linked highly swollen hybrid composite hydrogel systems ranges from 7.175 to 10.883. FT-IR analysis and SEM technique were applied for characterization. Sorption of a water-soluble cationic dye such as Janus Green B in the hydrogel systems was studied by the batch sorption technique at 25°C. For equilibrium sorption studies, adsorption percentage, dye removal capacity, and partition coefficient of the hydrogel systems have been investigated. The values of adsorption percentage of the hydrogels were ranged between 31.00% and 94.57%. Consequently, the hydrogel systems developed in this study could serve as a potential device for water and dye sorbents. C 2015 Wiley Periodicals, Inc. Adv Polym Technol 2016, 35, 21547; View this article online at wileyonlinelibrary.com.