In the present study, the synthesis of novel semi-interpenetrating network (Semi-IPN) hydrogel based on gum rosin alcohol-psyllium (GrA-Psy) has been reported. (Gum rosin alcohol-psyllium)-crosslinked-poly(acrylic acid) [termed as (GrA-Psy)-cl-poly (AA)] was synthesized using potassium persulphate (KPS) as an initiator and N, N-'-methylene-bis-acrylamide (MBA) as crosslinker by free radical graft co-polymerization technique. The prepared semi-IPN was characterized using FTIR, XRD, and FE-SEM. Further, the synthesized hydrogel was evaluated for the removal of malachite green (MG) dye from aqueous solution. Dye adsorption data was analyzed through various isotherm and kinetic models. Thermodynamic parameters and reusability of the synthesized adsorbent were also assessed. POLYM. ENG. SCI., 59:1416-1427 2019. (c) 2019 Society of Plastics Engineers