The aim of this work was the preparation of porous composite scaffold based on chitosan (Cht) and hydroxyapatite (HAp) for application in the Congo Red dye adsorption. Chitosan possesses high potential in waste water treatment as a cost-effective material derived from natural sources and its usage as a biosorbent is highly economical. In this work, the adsorption capacity of composite chitosan-hydroxyapatite scaffold was investigated and the results were compared with a commercial adsorbent (activated carbon). Synthesis of porous composite Cht-HAp scaffold with 30 mass% of HAp within chitosan matrix has been performed by a thermally induced phase separation method with gelation and extraction. Composition of prepared scaffolds were determined by Fourier-transforman spectroscopy and X-ray diffraction analysis, while the scaffold's morphology was imaged by scanning electron microscope. As an additional characterization of the scaffold, swelling capacity, compressive strenght and porosity were determined. The in situ formation of hydroxyapatite within the chitosan matrix and satisfying dye adsorption of Congo Red on the composite scaffold were confirmed. The impact of the initial concentration and temperature was studied on the removal of Congo Red dye. Further studies have confirmed good fitting of Freundlich and Temkin isotherms for chitosan and composite scaffolds, while Langmuir isotherm is suitable for adsorption on activated carbon.