Soybean trypsin inhibitor linked to Eudragit S-100 was used for the affinity precipitation of trypsin. Polymer and ligand concentrations used in conjugate preparation showed remarkable effect on the trypsin recovery. Trypsin precipitation efficiency amounted to 89% and recovery was 74%. The final purification of relatively crude commercial trypsin resulted in 1.85-fold purification. The SDS-PAGE analysis indicated significant purification. The precipitated enzyme activity was around 96% and recovered enzyme activity was 83%.