Hydrogels are three-dimensional (3D) network materials formed by the interaction between polymer and solvent molecules. The solvent immobilized within the 3D-polymer network is important as its presence prevents the collapse of the system and prevents the formation of a compact polymer mass. Chitosan-based hydrogels are hydrophilic, highly swollen and can absorb large amounts of water with drastically increased volume. The physicochemical properties of a hydrogel depend not only on the molecular structure of the gel and degree of cross linking but also on the content and state of water within the hydrogel. Chitosan materials are popular due to the fact that they are relatively inexpensive and exhibit many advantageous properties such as biocompatibility, biodegradability, non-toxicity, adsorption capacity and wide range of applications. Chitosan is the N-deacetylated derivative of chitin, although this N-deacetylation is almost never complete. The aim of the present study was to examine the ability of chitosan hydrogels to function as a sorbent for the extraction of a series of aminopyrydines (AP) from a nonpolar solvent (n-hexane). Chitosan hydrogels were prepared using glutaraldehyde as a cross-linking agent. Experiments were carried out to determine the maximum extraction efficiency, distribution coefficient, adsorption capacity, adsorption mechanism and desorption. The amount of aminopyridine extracted was a maximum (~ 100%) and the hydrogel affinity increased in the order of o-AP < m-AP < p-AP reflecting the combined effects of dipole and steric interactions and pK values. The data fitted the Langmuir adsorption model quite well and indicated adsorption capacities of 11.37 (o-AP), 21.03 (m-AP) and 29.33 (p-AP) mg/g of chitosan hydrogel. However, when the adsorption capacity is calculated on a per gram of chitosan basis, the values increase significantly (i.e., 323, 597 and 833 mg/g, respectively). In order to distinguish between physical and chemical adsorption, the equilibrium adsorption data were analyzed using the Dubinin-Radushkevich isotherm model. The mean adsorption energies for the aminopyridenes were 0.808, 0.204 and 0.116 kJ/mol, respectively, for p-AP, m-AP and o-AP. Mean absorption energies in this range are suggestive that the adsorption is predominantly due to physical processes. Desorption studies revealed that 100% of the o-AP could be desorbed from the chitosan hydrogel via use of methanol as solvent.